Money Hawaii, New York are strongest states for unions, S. Carolina and N. Carolina are weakest April 10, 2019 Michael B. Sauter, 24/7 Wall Street Comments Off on Hawaii, New York are strongest states for unions, S. Carolina and N. Carolina are weakest The share of American workers in trade unions fell once again in 2018, from 10.7% in 2017 to 10.5%. In 1983, 20% of workers belonged to labor unions.