Engaged in a two-front war, the United States was supplying not only its own military but those of the other Allies as well. Roosevelt wanted to prevent potential labor union strikes, which would slow industrial production and impede the war effort. The nation's urgent and massive conversion to a war economy had catapulted the United States out of the Great Depression, but the dramatic increase in employment also threatened to put labor unions and industrial leaders at odds over working conditions and wages.
The evolution of the NWLB illustrated the complexity of developing labor policy in the rapidly changing early-war years. It was formed in 1940 as the National Defense Advisory Board; later it became the Labor Division of the Office of the Production of Management (OPM), which morphed into the National Defense Mediation Board (NDMB) until 1942 when Roosevelt renamed the unit the National War Labor Board. The NWLB was made up of political, business and labor leaders and was tasked with providing labor-policy recommendations. Although the NWLB was established to mediate between parties involved in industrial disputes, Roosevelt also gave the board power to intercede and impose settlements in order to preempt any pause in production. The following October, Roosevelt issued the Order Providing for the Stabilization of the National Economy, which expanded the NWLB's control over wages and prices by stipulating that any adjustment of wages had to be cleared through it.
The Truman administration discontinued the National War Labor Board in 1946, giving labor-arbitration duties back to the National Labor Relations Board.