High school football in the Chicago area began in the mid-1880s. It became formalized in 1889 with the formation of the Cook County League, which included Chicago Manual, Lake View, Hyde Park, and Englewood. The schools played other schools, one another, and area colleges into the early 1900s and produced solid football talent.
The image below shows the 1891 league champion Englewood High School team, which included three team members who played for Dartmouth over the next few years, most notably Walter McCornack, who captained Englewood and Dartmouth (twice).
McCornack entered Dartmouth in 1893, playing freshman football and varsity baseball. Though only 5' 6" and 140 pounds, he started his sophomore season at quarterback until injuries to a halfback forced him to shift positions. He returned to quarterback for his junior and senior years. While they were sometimes competitive with the other future Ivy teams, they went 0-9-1 against them during his playing days.