The Taft-Hartley Act of 1947 amended the National Labor Relations Act to prohibit particular union activities. Among a suite of changes was a provision that empowered states to pass right-to-work laws, which prohibit union contracts that require employees to financially support a union as a condition of employment.[4] By the end of 1947, 12 states — Arizona, Arkansas, Florida, Georgia, Iowa, Nebraska, North Carolina, North Dakota, South Dakota, Tennessee, Texas and Virginia — had enacted right-to-work laws.[5]
In the 1950s, six more states — Alabama, Kansas Mississippi, Nevada, South Carolina and Utah — joined the fold. From then until 2012, state adoptions of right-to-work laws were rare. Wyoming joined in 1963, followed by Louisiana in 1976, Idaho in 1985 and then Oklahoma in 2001. It was not until 2012 that another spate of adoptions occurred, starting with Indiana in 2012, Michigan a year later, followed by Wisconsin in 2015, and West Virginia and Kentucky in subsequent years. Today, 27 of 50 states have right-to-work laws.[6]