Entrepreneur James Allison helped establish Indianapolis Speedway Team Co., 1915, and later built a precision machine shop here near speedway to improve race cars. Upon U.S. entry in WWI, 1917, 500-mile race was suspended and he devoted shop resources to war effort, including making parts for Liberty aircraft engines. Shop name became Allison Engineering Co. by 1921.
General Motors purchased company, 1929, and focused work on aircraft engines. During WWII, Allison Division built 70,000 liquid-cooled V-1710 engines for fighter aircraft. Company grew to over 23,000 employees and received awards for excellence in production. By mid-1940s, it manufactured jet engines and transmissions, which later played a key role in Korean War.