The union membership rate in the United States—the percentage of wage and salary workers who were members of unions—was 10.7 percent in 2016. Twenty-seven states and the District of Columbia had union membership rates below the U.S. average, while 23 states had rates above it.
Nine states had union membership rates below 5.0 percent in 2016, with South Carolina having the lowest rate (1.6 percent). The next lowest rates were in North Carolina (3.0 percent), Arkansas (3.9 percent), and Georgia (3.9 percent). New York (23.6 percent) was the only state with a union membership rate over 20.0 percent in 2016.
State union membership levels depend on both the employment level and the union membership rate. The largest numbers of union members lived in California (2.6 million) and New York (1.9 million). Over half of the 14.6 million union members in the U.S. lived in just 7 states (California, 2.6 million; New York, 1.9 million; Illinois, 0.8 million; Pennsylvania, 0.7 million; and Michigan, New Jersey, and Ohio, 0.6 million each), although these states accounted for only about one-third of wage and salary employment nationally.
Bureau of Labor Statistics, U.S. Department of Labor, The Economics Daily, Union membership rates by state in 2016 at https://www.bls.gov/opub/ted/2017/union-membership-rates-by-state-in-2016.htm (visited December 08, 2022).