 On September 7, 1919 Simpson won the 120 yd hurdles at the Knights of Columbus Olympics, an Armed Forces meeting held at Camp Dix, defeating former national champion Harold Barron; Simpson's time of 15.0 was the fastest in the world that year.A week later he won his second national championship title in the high hurdles, running 15.2 and beating Kelly and Barron; he also won the low hurdles in 24.4, his only national title in that event.Simpson became the University of Missouri's head track coach after the 1919 season; the move ended his career as an athlete in his own right, as track and field was in the era of amateurism and university coaches were considered professionals.