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In page University of Chicago:

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Harper recruited acclaimed Yale baseball and football player Amos Alonzo Stagg from the Young Men's Christian Association training school at Springfield to coach the school's football program.[11] Stagg was given a position on the faculty, the first such athletic position in the United States.[citation needed] While coaching at the university, Stagg invented the numbered football jersey and the huddle.[12] Stagg is the namesake of the university's Stagg Field.[citation needed]