South Carolina has the lowest union coverage rates of any state: Union coverage rates by state, 2023

State 2023 Union coverage
Hawaii 25.5%
New York 21.5%
Washington 18.1%
New Jersey 17.3%
California 16.9%
Connecticut 16.9%
Vermont 15.4%
Alaska 15.2%
Oregon 15.0%
Nevada 14.5%
Pennsylvania 14.2%
Michigan 14.1%
Minnesota 14.1%
Illinois 13.6%
Massachusetts 13.5%
Ohio 13.5%
Rhode Island 13.3%
Montana 13.0%
Maryland 12.8%
Kentucky 11.2%
New Hampshire 10.9%
Maine 10.8%
Kansas 10.5%
District of Columbia 10.4%
Missouri 10.4%
Delaware 10.1%
West Virginia 10.1%
Mississippi 9.8%
Nebraska 9.4%
New Mexico 9.0%
Indiana 9.0%
Iowa 8.7%
Alabama 8.6%
Colorado 8.6%
Utah 8.4%
Wisconsin 8.4%
Oklahoma 7.8%
North Dakota 7.5%
Tennessee 6.9%
Wyoming 6.6%
Florida 6.1%
Arkansas 5.8%
Virginia 5.6%
Texas 5.4%
Georgia 5.4%
Idaho 5.4%
Louisiana 5.1%
Arizona 4.8%
South Dakota 4.2%
North Carolina 3.3%
South Carolina 
3.0%

Source: EPI analysis of Current Population Survey (CPS).

View the underlying data on epi.org.