David Crosby was born in Phillipsburg, New Jersey on January 18, 1918.  He prepared for college at the Mercersburg Academy and entered Dickinson with the class of 1940.  Two years into his time at the College, during which he had become a member of Phi Kappa Psi fraternity, he transferred to Juniata College where he graduated in 1940.  He later earned a master's degree in sociology at the University of Southern California and returned to teach at Juniata during the summer session of 1941. 

By this time, however, he had already been accepted as a Marine Corps officer candidate.  In October, 1941, he entered training and was commissioned in February, 1942 at Quantico, Virginia.  He was assigned to the Pacific a few months later and, in early November 1942, was killed in action on Guadalcanal in the Solomon Islands.