He enrolled in Kenyon College, but left school after completing his freshman year to enlist as a private in the 52nd Ohio Infantry on August 12, 1862, but was not mustered into the service, initially because of his age.

On September 12 of that year, he was commissioned as a first lieutenant in the 6th Ohio Cavalry and assigned to the staff of Major General Thomas L. Crittenden in what later became the XXI Corps in the Army of the Cumberland.

He passed his bar exam and established a prosperous legal practice in New York City in the celebrated firm of Alexander & Green, eventually becoming a senior partner.

He joined the New York State Bar Association and served on the boards of directors for several prominent insurance companies, railroads, and financial institutions.

He was instrumental in establishing a formal statute for an intercollegiate system of academic costume, and provided the money in 1892 for the University of Kansas's first athletic stadium, McCook Field, which was in service for thirty years.