McKeen played football as a guard and end at the University of Tennessee from 1925 to 1927, where he earned all-state honors.

[1] From 1937 to 1938, McKeen coached at West Tennessee State Teachers College, now known as the University of Memphis, where he compiled a 13–6 record.

In 1940, he was named the SEC Coach of the Year after leading Mississippi State to its only undefeated season in school history.

He retired from coaching in 1948 after rendering his resignation to Mississippi State's athletic director, Dudy Noble.

[3] At the time of his departure from Starkville, McKeen was the winningest coach in Mississippi State history, a rank he would keep until Jackie Sherrill passed him during the 2000 season.