[4] President Harry S. Truman appointed Feinsinger to a presidential fact-finding board on December 31, 1945, along with Utah Supreme Court Chief Justice Roger I. McDonough and Missouri Supreme Court Chief Justice James M. Douglas, to investigate an ongoing labor dispute in the steel industry in which 700,000 steelworkers threatened to strike.
[5] After a general strike by maritime workers on the West Coast began in early September 1946, President Truman named Feinsinger as the federal government's chief mediator.
[6] Feinsinger played a critical role in settling a pineapple strike by Hawaiian workers which began on July 11, 1947.
[1][10] President Truman named Feinsinger chairman of the Wage Stabilization Board on August 15, 1951, succeeding George W. Taylor.
The board was part of a massive federal wage and price stabilization effort designed to support defense production and mobilization during the Korean War.
Feinsinger convinced United Steelworkers of America president Philip Murray to call off a strike set for January 1, 1952, in favor of a 90-day voluntary cooling-off and fact-finding period.
Feinsinger was forced to turn over the wage case to the president for resolution, but continued to work feverishly toward a solution.
On June 2, in a landmark decision, the United States Supreme Court ruled in Youngstown Sheet & Tube Co. v. Sawyer, 343 U.S. 579, that the president lacked the authority to seize the steel mills.
The strike lasted 55 days, and ended on July 24 on essentially the same terms the union had proposed four months earlier.
Feinsinger was appointed chairman of a three-member mediation panel by Mayor Robert F. Wagner Jr. and Mayor-elect John Lindsay.