The second day of practices at Yale, the coaching staff shifted Hill to linebacker on the freshman team and gave the quarterback job to Brian Dowling.

[4] Hill, who threw six halfback option passes for touchdowns at Yale, likened Dowling's athletic virtuosity to John Coltrane's musicality.

[5] Hill and Dowling led the 1968 Yale team to an undefeated season, ending its schedule in a famed 29-29 tie at Harvard.

[11] He got his chance at playing halfback in the second exhibition game, because the team was experiencing problems at running back during that training camp.

Don Perkins, the fourth leading rusher in NFL history had just formally announced his retirement, Dan Reeves the starter at halfback was struggling after having off-season knee surgery and his backup Craig Baynham had bruised ribs.

However, he hurt his toe while rushing for a team record 150 yards in a 41–28 victory over the Washington Redskins in the ninth game of the season.

[12] The Cowboys selected Duane Thomas in the first round of the 1970 NFL draft, because the team was not confident that Hill had recovered during the off season.

Hill played in Dallas for six seasons, helping the Cowboys win Super Bowl VI and 2 NFC titles.

He played in three WFL games in 1975, carrying the ball 49 times for 218 yards and no touchdowns, before suffering a torn medial collateral ligament in his right knee.

On April 3, 1976, Hill signed as a free agent with the Washington Redskins,[16][17] but he could not recapture his previous playing level.

In two seasons as a backup running back, he rushed for 558 yards and caught 25 passes, before announcing his retirement on August 7, 1978.

In 1987, Baltimore Orioles owner Edward Bennett Williams appointed Hill to the team's board of directors.

Hill has written several articles on sports and academia for national publications, makes appearances at university campuses and business firms, throughout the United States.

He addresses several topics including the problem of drugs and alcohol and the work needed in this area, and the important relationship of sports and academia.

[23] The Calvin Hill Day Care Center in New Haven was founded by fellow Baltimore, Maryland-native Kurt Schmoke among other undergraduates in 1970 and is named in his honor.