For some reason, I was just watching clips of a Northwestern v. Minnesota game from 1930 on You Tube. About halfway through, I noticed that one of Northwestern’s players was not wearing a helmet! All of the other players wore leather helmets, but this tough guy ran around pile diving with his brown locks flowing. 

I looked up the story and apparently the player was Edgar Manske. Not only was Manske the last player in college to play without a helmet, he went on to be the last guy in the NFL to do the same.

From Manske’s wiki bio:

Manske was involved in a trade considered among the most lopsided in NFL history.[5] In 1938, he was traded from Chicago to the Pittsburgh Steelers for the Steelers' first-round selection (#2 overall) in the upcoming 1939 NFL draft. The Bears then drafted future Hall of Fame quarterback Sid Luckman. Manske re-signed with the Bears later in 1939, leaving Pittsburgh with nothing to show for its top pick.

The Manske story reminds me of when I was a kid and a few of the old time guys in the NHL still played without a helmet/face guard because they were able to exercise a grandfather clause. The last holdout was Craig MacTavish, who finally retired after the 1996-97 season. MacTavish was a very good player and is now VP of operations for the Edmonton Oilers, but he was also guilty of vehicular manslaughter (DUI) in the mid-80s and got a very lenient sentence.