Although the Marauder did not make its first flight until November 25, 1940, its design showed such promise that 1,131 B-26s were ordered by the Army Air Corps in September 1940.The airplane began flying combat missions in the Southwest Pacific in the spring of 1942, but most of the B-26s subsequently assigned to operational theaters were sent to England and the Mediterranean area.

Bombing from medium altitudes of 10,000 to 15,000 feet, the Marauder had the lowest loss rate of any Allied bomber - less than one-half of one percent. By the end of WW II, it had flown more than 110,000 sorties and had dropped 150,000 tons of bombs, and had been used in combat by British, Free French, Australian, South Africa, Canadian, and Greek forces in addition the U.S. units. In 1945 when B-26 production was halted 5,266 had been built.