Among the engineers fueling the rapid rise of the automotive industry at the dawn of the 20th century was James Allison, a fountain pen maker who joined with Carl G. Fisher in 1904 to found Prest-O-Lite, an early manufacturer of the power source for automotive headlights. This biography tracks Allison's involvement in the Indianapolis 500, which he cofounded with Fisher and two others, as well as his machine shop's construction of the Liberty engine, the first mass-produced aircraft engine, and also the V1710, the workhorse of World War II military aircraft. Through his unique ingenuity and perseverance, Allison created a legacy that still resonates today at the Indianapolis 500, Rolls-Royce, and Allison Transmission.