Ingwersen received a scholarship to play football at the University of Illinois. He played under Robert Zuppke from 1917 to 1919. During his time at Illinois, the Illini won two Western Conference titles and the 1919 National Championship. After college, he played one year of professional football in the NFL’s debut year for George Halas at the Decatur Staleys. Later the Staleys were renamed the Chicago Staleys (1921) and then the Chicago Bears (1922).
Iowa’s hiring of Ingwersen as head coach was met with controversy. Iowa had almost lured Notre Dame’s head coach, Knute Rockne, but when the Chicago Tribune ran an article on the possibility, Notre Dame was quick to offer him a ten-year extension which he took. Ingwersen was then hired despite many fans calling him a traitor for having played for Illinois despite being born in Iowa.
Iowa was suspended from the Big Ten in January of 1930 due to a recruiting scandal that stretched back to the Howard Jones era. Iowa had to suspend the players who had been paid by alumni’s and fire athletic director Belting, who was implicated in the scheme. Iowa was reinstated a month later. Losing the players to suspension greatly inhibited Iowa’s performance which led to a 1-6-1 record in 1931 and just seven points scored all season long. Iowa’s program was a long way off from being competitive again. Ingwersen resigned after that season saying he “did not care to fight the critics who are now or will be asking for a new coach at Iowa.” He finished with a 33-27-4 record at Iowa with two losing seasons in eight years.