Final answer:
The Norris-LaGuardia Act declared yellow dog contracts unenforceable. The Wagner Act supported collective bargaining and created the NRLB to enforce labor rights. It played a significant role in empowering American labor unions.
Step-by-step explanation:
The Norris-LaGuardia Act declared yellow dog contracts unenforceable. These types of contracts were agreements that employees would not join a labor union as a condition of employment. Significant American labor legislation like the Wagner Act, formally known as the National Labor Relations Act, reaffirmed workers' rights to organize and to collectively bargain with employers.
The Wagner Act also resulted in the creation of the National Labor Relations Board (NLRB) to enforce its provisions and settle disputes between unions and employers. Despite challenges, it was upheld by the Supreme Court in 1937 and became a staple in the foundation of labor law and the empowerment of unions in the United States.