The percentage of American workers in unions remained effectively unchanged last year. This marks a departure from the nation’s long-term trend. In the past 30 years, union membership has dropped from 20.1% of the workforce in 1983 to 11.2% last year.

Despite this long running decline, some states remain union strongholds, while others have almost no union presence. In New York, Alaska and Hawaii, more than 22% of workers were union members last year. Conversely, in five states, less than 4% of all employees were union members.

Click here to see the states with the strongest (and weakest) unions

A number of factors help determine whether unions have a significant or negligible presence in a state, including industry composition, labor laws and political atmosphere. Based on data collected by the Bureau of Labor Statistics and calculations by Unionstats.com, 24/7 Wall St. identified the states with the highest and lowest shares of workers who are union members.

With the addition of Michigan in 2012, nearly half of all states have so-called “right to work” laws. These laws prohibit employers from requiring union membership as a prerequisite for employment. As a result, employees often elect not to pay union fees. All 10 of the states with the lowest proportional union membership have right to work laws. Conversely, just two of the 10 states with the highest rates of union membership — Michigan and Nevada — have such laws.

However, according to an email from Unionstats founder Barry Hirsch, while these laws can weaken a union’s financial base, the impact may be smaller than some suggest. “Right to work is important symbolically as a sign of a pro-business [or] anti-union environment,” Hirsch added.

The number of union workers in a state depends in large part on the representation of government employees. Although the public sector is far smaller than the private sector in terms of total employment, public sector workers are far more likely to be members of a union. Nationwide, more than 35% of public sector employees — which include teachers, firefighters, police officers and postal workers — were union members last year.

As a result, states where public employees were more likely to be in unions had higher rates of overall union representation. In New York, the nation’s most unionized state, 70% of public sector employees were union members, the highest percentage in the nation. By contrast, in North Carolina, the nation’s least unionized state, slightly less than 10% were union members.

In contrast to the public sector, unions are far less prevalent in the private sector, where just 6.7% of the workforce was unionized. However, because the private sector is far larger, it still accounts for a large share of union membership. In fact, most of the top 10 states for overall membership were also among the top 10 for percentage of private sector workers who were union members.

In recent decades, the private sector has accounted for the majority of the decline in the union workforce, while the share of public sector workers in unions has remained relatively constant, Hirsch wrote. “Public sector members now account for half of all members despite being only [one-sixth] of the workforce,” he added.

Often, high levels of union membership in a state were due to the presence of industries where unions traditionally held considerable influence, most notably construction and manufacturing. As of 2013, 14% of all construction sector workers, and 10% of all manufacturing workers, were union members.

In the past decade, the share of private sector workers in unions fell in all but a handful of states. From 2003 to 2013, the number of private sector union members dropped by more than 1 million, from just less than 8.5 million to 7.3 million. In the same time, manufacturing union membership slipped by 34%, from just under 2.2 million to 1.4 million.

In addition to sector composition, Hirsch also noted that history played a role in determining unionization rates. “States that historically had high unionization in manufacturing are now more likely to have high unionized hospitals and grocery stores, and vice-versa,” he explained. In turn, when young workers have not been exposed to unions through friends and family members, “these workers are far less likely to support union organizing.”

Based on figures published by Unionstats.com, an online union membership and coverage database, 24/7 Wall St. identified the states with the highest and lowest union membership as a percentage of total employment. The database, which analyzes Bureau of Labor Statistics’ (BLS) Current Population Survey, provides labor force numbers and union membership in both the public and private sector, including manufacturing and construction. Additionally, 24/7 Wall St. reviewed annual average unemployment rates for each state from the BLS, as well as income and poverty data from the 2012 American Community Survey, produced by the U.S. Census Bureau.

These are the states with the strongest and weakest unions.

States with the Strongest Unions

10. Nevada
> Pct. of workers in unions: 14.6%
> Union workers: 168,323 (24th highest)
> 10-yr. change in union membership: 23.7% (2nd highest)
> Total employment, 2013: 1,152,609 (18th lowest)

The number of union workers in Nevada rose by more than 32,000 between 2003 and 2013. During that time, employment in Nevada grew by 22.3%. Only Utah had higher employment growth than Nevada during those years. The share of private construction workers union members rose from 18.7% to 23.6% between 2003 and 2013, a higher percentage points increase than all but three other states. As of last year, 11% of Nevada’s private sector employees were union members, among the highest percentages in the country. State residents still face a difficult job market. Nevada’s unemployment rate of 9.8% was an improvement from the 11.5% unemployment rate in 2012, but it remained the highest in the nation.

9. Illinois
> Pct. of workers in unions: 15.7%
> Union workers: 850,557 (3rd highest)
> 10-yr. change in union membership: -12.0% (18th lowest)
> Total employment, 2013: 5,402,987 (6th highest)

Although the number of union employees in Illinois fell by 12% between 2003 and 2013, Illinois remains one of the nation’s most unionized states. More than 850,000 workers in the state were union members, more than in any other state except for California and New York. More than 36% of the state’s manufacturing sector workers were union members as of last year, a higher percentage than in any other state. Historically, Illinois is one of the pioneering states for labor unions. The state is the site of the historic Haymarket Square riot in 1886 and the Pullman strike in 1894 — pivotal moments in the industrial revolution and labor movement.

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8. New Jersey
> Pct. of workers in unions: 16.0%
> Union workers: 610,187 (6th highest)
> 10-yr. change in union membership: -17.2% (12th lowest)
> Total employment, 2013: 3,815,813 (11th highest)

More than 60% of New Jersey’s public sector workers were union members, a higher proportion than all state except for New York and Rhode Island. The state’s teachers union, the New Jersey Education Association, has more than 192,000 members. The state’s construction sector, too, had relatively high union membership. Nearly one-quarter of New Jersey’s private construction sector workers were union members last year, more than in all but a handful of states. In all, New Jersey had 45,000 union members working in the construction sector last year.

7. Michigan
> Pct. of workers in unions: 16.2%
> Union workers: 631,453 (5th highest)
> 10-yr. change in union membership: -31.3% (4th lowest)
> Total employment, 2013: 3,890,636 (9th highest)

The number of union members in Michigan decreased by more than 31% between 2003 and 2013, among the largest drops in the country. Nevertheless, the state remains one of the largest union strongholds in the U.S., with 11% of its private sector workers union members, among the most in the country last year. Home to Ford, Chrysler and General Motors, Michigan is also home to the United Auto Workers (UAW), one of the largest labor unions in the United States. The UAW has 390,000 active and 600,000 retired members. Michigan has struggled for years with high unemployment rates. The state’s unemployment rate was 8.8% in 2013, one of the highest rates in the nation.

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6. California
> Pct. of workers in unions: 16.4%
> Union workers: 2,429,109 (the highest)
> 10-yr. change in union membership: 0.6% (17th highest)
> Total employment, 2013: 14,840,395 (the highest)

Even as it declined nationwide, union membership in California actually increased slightly between 2003 and 2013, rising by 0.6%, or nearly 15,000 members. Union membership in the private sector was little changed, as the number of union members working in construction declined from roughly 170,000 to 119,000 during that time. However, union membership in the public sector rose during that time, increasing slightly to reach more than 1.3 million despite recent cuts in government employment. As of last year, 55% of public sector workers were union members, among the highest proportions in the nation. The state continues to struggle with job creation. California’s unemployment rate of 8.9% in 2013 was one of the highest in the country.

5. Rhode Island
> Pct. of workers in unions: 16.9%
> Union workers: 77,367 (18th lowest)
> 10-yr. change in union membership: -7.9% (25th highest)
> Total employment, 2013: 458,494 (8th lowest)

Like several other states with strong union presence, nearly two-thirds of Rhode Island’s public sector belonged to a union last year, second only to New York. Labor initiatives appear to be a recent priority for policy makers. The state raised its minimum wage to $8 an hour at the beginning of last year, affecting more than 10,000 workers at the time. Wages may increase even further if the labor union-backed legislation introduced in January is passed. The bill aims to increase the minimum wage to $10 per hour by 2016. While union membership may benefit many Rhode Island workers, high wages could potentially also limit new employment opportunities. Rhode Island’s unemployment rate of 9.5% last year was higher than that of any other state except for Nevada.

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4. Washington
> Pct. of workers in unions: 18.9%
> Union workers: 544,986 (8th highest)
> 10-yr. change in union membership: 8.7% (8th highest)
> Total employment, 2013: 2,880,935 (14th highest)

Washington’s total employment rose by nearly 104,000 workers, or 3.6%, between 2012 and 2013, one of the highest increases in the country. Washington is one of the most unionized states in the private sector, with 11.7% of all employees union members. Nearly one-quarter of the state’s private construction workers were union members in 2013, among the highest in the country. Similarly, 24.2% of all manufacturing workers held union membership, the most in the nation. There were 52,000 fewer public sector employees in 2013 than in 2012, as the state continued to follow through on the budget cuts it initiated during the recession. Despite this, union membership in the public sector held steady, at more than 261,000 workers, or 57% of all public employees.

3. Hawaii
> Pct. of workers in unions: 22.1%
> Union workers: 121,357 (23rd lowest)
> 10-yr. change in union membership: -0.3% (18th highest)
> Total employment, 2013: 549,219 (9th lowest)

As is the case in many states with strong union membership, a large proportion of Hawaii’s manufacturing workers — 18.3% — were union members as of last year, more than in all but two other states. More than 32% of private construction workers were also union members, among the highest percentages nationwide in 2013. By many measures, Hawaii is a good place to work, with high median incomes and low unemployment helping to offset the state’s exceptionally high cost of living last year. A typical household made more than $66,000 in 2012, more than in all but a handful of states. And the unemployment rate was just 4.8% last year, also among the best rates.

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2. Alaska
> Pct. of workers in unions: 23.1%
> Union workers: 70,692 (16th lowest)
> 10-yr. change in union membership: 19.6% (3rd highest)
> Total employment, 2013: 306,322 (3rd lowest)

More than 23% of Alaska’s relatively small workforce, or 70,692 workers, were union members in 2013, more than in any state except for New York. Additionally, more than one in 10 private sector workers were union members, among the higher rates in the nation. Unlike many highly unionized states, union membership increased in Alaska — by nearly 20% — between 2003 and 2013. This was the third largest increase in union members among all states. Membership across the nation, by contrast, fell by 8% over that time. Alaska residents had among the nation’s highest incomes as of 2012, when a typical household earning more than $67,000. Also, just slightly more than 10% of people lived below the poverty line that year, among the lowest in the country.

1. New York
> Pct. of workers in unions: 24.3%
> Union workers: 1,982,771 (2nd highest)
> 10-yr. change in union membership: 2.4% (14th highest)
> Total employment, 2013: 8,144,204 (3rd highest)

Nearly one-quarter of New York’s workers — close to 2 million people — were union members in 2013, the highest percentage in the country. Union representation was relatively strong both in the private sector and in government jobs. In the private sector, 15.1% of workers were union members, the highest percentage in the country. Nearly 70% of public sector workers belonged to unions, the highest percentage in the country. However, even in New York, unions have been forced to make concessions so that their members could keep their jobs. In 2011, the state struck a deal with New York’s largest public employees union, the Civil Service Employees Association, to freeze wages in order to avoid mass layoffs.

States with the Weakest Unions

10. Arizona
> Pct. of workers in unions: 5.0%
> Union workers: 121,864 (24th lowest)
> 10-yr. change in union membership: 7.8% (9th highest)
> Total employment, 2013: 2,455,146 (21st highest)

The total number of union workers in Arizona rose from slightly more than 113,000 in 2003 to 121,864 last year, a nearly 8% gain. However, union membership growth failed to keep pace with overall job growth in the state, as total employment rose 12% between 2003 and 2013. As was the case in many states, disparities in public sector and private sector membership were pronounced. As of last year, 16.2% of public sector workers were union members, versus just 2.9% of private sector workers. Recently, several public sector unions in Phoenix were the subject of controversy after the city was accused of tolerating “pension spiking,” a practice that inflates salaries in the years before retirement in order to later receive higher pension payments

9. Texas
> Pct. of workers in unions: 4.8%
> Union workers: 517,825 (9th highest)
> 10-yr. change in union membership: 1.9% (15th highest)
> Total employment, 2013: 10,880,079 (2nd highest)

Union membership in Texas was miniscule in both the public and private sectors last year. Just 2.6% of the state’s 9.3 million private sector employees were union members, lower than in all but a handful of states, and well below the U.S. average of 6.7% in that sector. In private construction, an industry that is often heavily unionized, just 2.8% of workers were union members. By comparison, 14.1% of private construction workers nationwide were union members. Leaders from unions, including the AFL-CIO, the largest federation of labor unions in the United States, convened in February to discuss how to increase union membership in the state.

8. South Dakota
> Pct. of workers in unions: 4.7%
> Union workers: 17,206 (2nd lowest)
> 10-yr. change in union membership: -9.7% (21st lowest)
> Total employment, 2013: 362,526 (5th lowest)

Compared to 2003, the number of employed residents had increased by 2013 — as it did in most states. Union membership, on the other hand, decreased considerably, by 10% between 2003 and 2013. Out of the more than 362,526 employed South Dakotans, just 17,206 were union members last year, lower than every state except for Wyoming. South Dakota’s unemployment rate, in any case, was remarkably low last year, at just 3.8%, second only to North Dakota.

7. Idaho
> Pct. of workers in unions: 4.7%
> Union workers: 29,021 (4th lowest)
> 10-yr. change in union membership: -24.9% (6th lowest)
> Total employment, 2013: 617,100 (11th lowest)

Just 4.7% of Idaho workers were union members last year, down from 7% of workers in 2003. In that time, union membership fell by nearly 10,000 workers, accounting for a nearly 25% drop in one of the nation’s smaller states. By contrast, total employment in Idaho jumped by 12.5% between 2003 and 2013, one of the largest increases nationwide, despite the decline in employment the state experienced during the Great Recession. As of last year, 29,021 workers in the state were union members, of which 17,404 worked in the public sector.

6. Louisiana
> Pct. of workers in unions: 4.3%
> Union workers: 74,826 (17th lowest)
> 10-yr. change in union membership: -31.5% (3rd lowest)
> Total employment, 2013: 1,728,929 (25th lowest)

In Louisiana, one of the poorest states in the country, and it is little surprise that union membership is quite low. Just 12.7% of public workers in the state were union members last year, far lower than the 35.5% of public workers nationwide. Nearly 20% of its residents lived below the poverty line at some point in 2012, one of the highest poverty rates in the country. State politicians have largely been perceived as being anti-union. The state enacted its right to work law in 1976, prohibiting unions from making deals with employers that would require the hiring of union members.

5. Utah
> Pct. of workers in unions: 3.9%
> Union workers: 49,253 (10th lowest)
> 10-yr. change in union membership: -7.1% (24th highest)
> Total employment, 2013: 1,252,176 (19th lowest)

Just 3.9% of Utah employees were part of a union in 2013, while just 5.4% were considered covered by a union contract, both among the lowest rates in the nation. While this was lower than in 2003, when 5.2% of workers were in unions, the actual number of union workers fell by just 3,000 in that time. Notably, much of the loss in union jobs has come from the public sector, where the percentage of workers in a union dropped from 19.9% to 11.7%, one of the lowest rates in the nation. This alone accounted for a loss of nearly 10,000 union members. While unions play a minor role in Utah’s labor force, the state’s job market remains robust. Employment in the state jumped 23.4% between 2003 and 2013, the most of any state. The state’s annual average unemployment rate was just 4.4% in 2013, fourth lowest in the nation

4. South Carolina
> Pct. of workers in unions: 3.7%
> Union workers: 68,484 (15th lowest)
> 10-yr. change in union membership: -4.0% (23rd highest)
> Total employment, 2013: 1,854,629 (24th highest)

According to the Center for Economic and Policy Research, South Carolina is one of just a few states where police officers, firefighters, teachers and all other public employees are prohibited from collective bargaining. It is therefore no surprise that so few of South Carolina workers are union members. Governor Nikki Haley openly discourages unions, stating that eliminating unions is part of her job description. In a recent news report, Haley said, “we discourage any companies that have unions from wanting to come to South Carolina because we don’t want to taint the water.” Just 3.7% of workers belonged to unions last year, including just under 10% of public sector workers, lower than in all but a few other states.

3. Mississippi
> Pct. of workers in unions: 3.6%
> Union workers: 37,856 (7th lowest)
> 10-yr. change in union membership: -31.6% (2nd lowest)
> Total employment, 2013: 1,040,242 (16th lowest)

Just 4.9% of public sector workers in Mississippi belonged to a union in 2013, the lowest percentage in the country, and far lower than the average 35.3% of public workers in the U.S. as a whole. Just 5.7% of the state’s private construction workers were union members last year, compared to 14.1% in the U.S. as a whole. The state also had the lowest median household income in the country at $37,095 in 2012, as well as the second highest percentage of residents using food stamps, 19.4%. State lawmakers recently passed a bill that restricts mass picketing by union members at a business or residence. A similar bill also outlaws unions from coercing companies to take a neutral stance during union membership drives.

2. Arkansas
> Pct. of workers in unions: 3.5%
> Union workers: 37,735 (6th lowest)
> 10-yr. change in union membership: -24.2% (7th lowest)
> Total employment, 2013: 1,072,119 (17th lowest)

Arkansas had the second lowest percentage of unionized private sector workers in 2013 at just 1.4%, far lower than the 6.7% for the United States as a whole. The state also had among the lowest percentages of unionized workers in the public sector, at 10.9%. The percentage was among the lowest in the country and far below the 35.3% average in the United States. In addition to low union membership figures, the state has struggled to grow jobs over the past several years. Roughly 83,000 workers lost or left their employment between 2012 and 2013, one of the largest declines in the country. The state’s public sector had a net loss of nearly 9,000 employees in that time, including a decline of 18,000 in private construction, among the steepest losses in the nation.

1. North Carolina
> Pct. of workers in unions: 3.0%
> Union workers: 116,178 (22nd lowest)
> 10-yr. change in union membership: 4.3% (12th highest)
> Total employment, 2013: 3,881,111 (10th highest)

Just 3% of North Carolina’s workforce was part of a union last year, less than in any other state. Unsurprisingly, North Carolina is a right to work state, which means employees are not required to join or pay dues to unions. North Carolina is one of just three states with blanket statutes prohibiting collective bargaining for all public-sector employees. Union participation in the two sectors with usually the most collective bargaining — construction and manufacturing — is nearly non-existent in North Carolina. There were no union members among private construction workers at all last year, and just 2.3% of manufacturing workers belonged to a union, last and third-to-last, respectively.

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