Taft-Hartley Act
The Labor–Management Relations Act is a United States federal law
Law of the United States
The law of the United States consists of many levels of codified and uncodified forms of law, of which the most important is the United States Constitution, the foundation of the federal government of the United States...

 that monitors the activities and power of labor unions
Trade union
A trade union, trades union or labor union is an organization of workers that have banded together to achieve common goals such as better working conditions. The trade union, through its leadership, bargains with the employer on behalf of union members and negotiates labour contracts with...

. The act
Act of Congress
An Act of Congress is a statute enacted by government with a legislature named "Congress," such as the United States Congress or the Congress of the Philippines....

, still effective, was sponsored by Senator Robert Taft
Robert Taft
Robert Alphonso Taft , of the Taft political family of Cincinnati, was a Republican United States Senator and a prominent conservative statesman...

 and Representative Fred A. Hartley, Jr.
Fred A. Hartley, Jr.
Fred Allan Hartley, Jr. was an American Republican Party politician from New Jersey. Hartley served ten terms in the United States House of Representatives where he represented the New Jersey's 8th and New Jersey's 10th congressional districts...

 and became law by overriding U.S. President Harry S. Truman
Harry S. Truman
Harry S. Truman was the 33rd President of the United States . As President Franklin D. Roosevelt's third vice president and the 34th Vice President of the United States , he succeeded to the presidency on April 12, 1945, when President Roosevelt died less than three months after beginning his...

's veto
A veto, Latin for "I forbid", is the power of an officer of the state to unilaterally stop an official action, especially enactment of a piece of legislation...

 on June 23, 1947; labor leaders called it the "slave-labor bill" while President Truman argued that it was a "dangerous intrusion on free speech," and that it would "conflict with important principles of our democratic society," Nevertheless, Truman would subsequently use it twelve times during his presidency.