Final answer:
The National Labor Relations Board was established by the National Labor Relations Act of 1935, commonly referred to as the Wagner Act.
Step-by-step explanation:
The National Labor Relations Board (NLRB) was created by the National Labor Relations Act of 1935, also known as the Wagner Act. Authored by New York Senator Robert Wagner, the Act aimed to protect the rights of workers to form unions and bargain collectively with their employers.
The legislation established the NLRB as a federal agency responsible for enforcing the Act's provisions, which included handling disputes between unions and employers and prohibiting certain unfair labor practices.