[1][2] The law also created the Bituminous Coal Labor Board to regulate maximum work hours and minimum wage[1] but was later ruled to be unconstitutional in Carter v. Carter Coal Co. because the Supreme Court did not find the law's labor provisions to qualify as interstate commerce and therefore considered its actions beyond the jurisdiction of the federal government.
[3] In 1939, the Bituminous Coal Commission was abolished, and its duties were transferred to the US Department of the Interior.
[4] The Act increased profits, wages, and union membership, and reduced strikes.
Conservatives feared it would set a precedent for regulation to affect other industries and thus questioned if it was constitutional.
Large consumers of coal also argued it would unreasonably increase prices, and operators from the south and west said it discriminated against low-wage and non-union mines.