The steel strike of 1959 was a 116-day labor union strike (July 15 – November 7, 1959) by members of the United Steelworkers of America (USWA) that idled the steel industry throughout the United States. The strike occurred over management's demand that the union give up a contract clause which limited management's ability to change the number of workers assigned to a task or to introduce new work rules or machinery which would result in reduced hours or numbers of employees. The strike's effects persuaded President Dwight D. Eisenhower to invoke the back-to-work provisions of the Taft-Hartley Act. The union sued to have the Act declared unconstitutional, but the Supreme Court upheld the law.The union eventually retained the contract clause and won minimal wage increases. On the other hand, the strike led to significant importation of foreign steel for the first time in U.S. history, which replaced the domestic steel industry in the long run. The strike remained the longest work stoppage in the American steel industry until the steel strike of 1986.