Killed in a midget car crash, when his car overturned. Full name was Aloysius. He originally worked as a racing mechanic before progressing as a driver. His career was often marred by big crashes and subsequent injuries. After Theisen's death, a race in Michigan was renamed in his honour. Theisen began racing in 1925 and was best at dirt track racing, winning races at Lansing Speedway close to home, but also took wins in Indiana, Ohio and Illinois. In 1934, he took the AAA Mid-Western Dirt Track Championship.

Biography last updated 17 Jan 2017