Born in Manhattan to privilege, Harrison became a physician and surgeon. He served as an Army surgeon in the Mexican-American War, and otherwise ran a private practice from his Waverly Place home.
As a young man he met Ethan Middleton, originally of Paradise in Hamilton county. A loving, committed relationship developed between them, but Harrison could not overcome what he saw as duty to his family. He married the young woman they picked out for him, and Ethan returned to Paradise.
Later in life, after the deaths of Ethan and of Harrison’s wife, he entered into a marriage of convenience with Ethan’s cousin Lily Bonner Ballentyne, a widow.