Harry Joseph O'Brien (October 31, 1884 â August 23, 1955), nicknamed "Shorty", was an American college football, college basketball, and college baseball coach. He was the fifth head football coach at The Citadel, serving for five seasons, from 1916 to 1918 and from 1920 to 1921, compiling a record of 14âÂÂ15âÂÂ4. O'Brien also coached basketball and baseball for The Citadel for two seasons during World War I. He tallied a record of 6âÂÂ2 in basketball and 3âÂÂ9 in baseball. O'Brien died of coronary thrombosis on August 23, 1955, at his home in Philadelphia.