What significant change regarding unions was enacted with the passage of the Taft-Hartley Act?

The significant change brought about by the Taft-Hartley Act is that unions were prohibited from engaging in unfair labor practices. This legislation was enacted in 1947 as a response to some of the excesses of organized labor that were perceived during the preceding decades. The Act aimed to balance power between labor and management, promoting fair conduct within labor practices.

By prohibiting unions from participating in unfair labor practices, the Taft-Hartley Act ensured that labor organizations were held accountable for their actions, just as employers were already subject to regulations against unfair labor practices under the National Labor Relations Act. This helped to protect workers' rights while preventing abuses by unions, establishing a more equitable framework for labor relations in the United States.

This shift was significant in averting potential abuses of power by union leadership, thus reinforcing a system that promotes fairness and integrity in labor relations.