The Labor–Management Relations Act was enacted June 23, 1947, informally
the Taft–Hartley Act is a United States federal law that monitors the activities
and power of labor unions.  The act, still effective, was sponsored by Senator
Robert Taft and Representative Fred A. Hartley, Jr. and legislated by overriding
U.S. President Harry S. Truman’s veto 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,” Truman would subsequently use it twelve times during
his presidency. The principal author of the Taft–Hartley Act was J. Mack Swigert
of a Cincinnati law firm.

Ohio Senator Robert Taft

Rep. Fred A. Hartley, Jr. of N.J.