Born and raised in Davenport, Iowa, Hillebrand played scholastically at Central High School.

[1] He played collegiately for the Colorado Buffaloes,[2] where, as a senior, he was honored as a first-team All-American by both the Associated Press (AP) and the Football Writers Association of America (FWAA).

[3][4] Hillebrand was selected by the New York Giants in the first round (13th overall) of the 1962 NFL draft.

[6] He chose to sign with the Giants, but his rookie training camp was interrupted by a six month hitch in the Marine Corp, from February to August.

[8] Hillebrand is no relation to the Giants' 1944 first-round draft pick, Billy Hillenbrand.