|Kelso was born in Baltimore, Maryland, December 15, 1903. He attended Baltimore City College, graduating in 1921. He then attended Johns Hopkins University, receiving an BA degree in 1925, MA degree in 1927, and a Ph.D. degree in 1929. Kelso became an Associate Professor of Mathematics in 1950 and was appointed to be Dean of Students in 1959 - a position he held until his retirement in 1967. Kelso was a member of the Kappa Alpha fraternity, Omicron Delta Kappa Leadership Society, Sigma Xi Scientific Society, American Mathematic Society, and Mathematical Association of America, and was Hopkins representative to the Board of Directors of the YMCA.
At Hopkins, he won four letters in lacrosse. The 1925 team won the Silver Medal and the 1926 and 1927 teams were both national champions. After finishing his college career, he played for the Mt. Washington Club and the Baltimore Olympic Club, and started his coaching at the old Marstons School. He also coached at Park School and Towson High School before becoming affiliated with the coaching staff at the Johns Hopkins University. His coaching career at Hopkins was extremely successful. The 1932, 1933, 1934, 1941 and 1950 teams were national champions.
Kelso's interest in lacrosse did not stop with his coaching. He had been one of the most active members of the USILA in the history of the association. He coached for a period of 25 years, officiated for 10 years, and served as president of the Southern Lacrosse Officials Association for one year. He had been chairman of the following committees of USILA: All-American Committee 1956-58; Coach of the Year Committee 1960-81; Championship Committee 1960-62; Film Committee since 1951. He had been a member of the Executive Board of the USILA and also a member of the Lacrosse Hall of Fame Foundation, Inc. He served on the Rules Committee on several occasions. At the time of his death, Kelso was chairman of the Championship Awards Committee, a position that he had held since 1960. He has coached several all-star prep school teams and has served as head coach of the North-South Game.
Kelso has directed two educational films, "How to Play Lacrosse", and "Fouls of Lacrosse." He participated in making "File 7," a television picture on Hopkins lacrosse. He made many talks to high school students in both Baltimore City and Baltimore County on the game of lacrosse. In 1953 he received the trophy awarded to the man who had done the most for lacrosse. He has also received the Kelly Post Award for the Baltimore Citizen who has contributed a great deal to lacrosse over the years. He is the author of a book called "Lacrosse", which was published by the Barnes Company in 1951.
Kelso married Mary Clare Kirk in 1934, and they had two children, William Kelso Morrill, Jr. and Jean Elizabeth. Bill was an All-American at Hopkins for three years (1957-59). He graduated from Hopkins and also the Harvard Business School.
Kelso Morrill passed away on April 11, 1968.