The U.S. military also used motorcycle sidecar rigs, the first appearing in WW I combat as a machine gun-equipped sidecar unit. The two-man crew consisted of rider plus gunner who fired from a seated position in the sidecar.
Thousands of motorcycles were furnished to the armed forces and other government agencies during WW I. About 41,000 of these were Indian's. The first 20,000 had been contracted for by the War Department at $187.50 for solo machines and $47 additional for the sidecar. Harley-Davidson made some 15,000 motorcycles for the war effort while a lesser number were Excelsior's and Cleveland's.
By the 1920’s, mass production and assembly techniques used in the American auto industry drastically cut the cost of building cars. This enabled car makers to price their products within reach of ordinary working people. As a result Jeeps displaced motorcycle/sidecar units in our military.
Around the world the Marine Corps began to use motorcycles primarily for messenger, convoy & military police duties.
The primary manufacturer of motorcycles for the U.S. military during World War II was Harley-Davidson who began producing the WLA in their Milwaukee, WI factory in 1940. During the war, Harley-Davidson produced more than 88,000 WLAs, shipped to U.S. forces as well as to Allies (especially the Soviet Union) under Lend-Lease.
Equipped with Model UA Harley-Davidsons sidecar rigs, the Motorcycle Marines delivered machine guns, ammunitions and first aid supplies, transported the wounded and escorted convoys of ammunition trucks in conflicts ranging from The Vietnam War to The Persian Gulf's Desert Storm, where terrain issues often favored a motorcycle with sidecar over a wider Jeep vehicle.
