After his discharge he went to Europe, where he studied the Asiatic Cholera. On September 3, 1867, he married Rebecca Medwin Copcutt, a daughter of Yonkers, New York, industrialist John Copcutt (1805–1895) at the historic John Copcutt Mansion. Until his retirement in 1928, Dr. Leale maintained a continuous interest in philanthropic, medical, and scientific projects. Leale was one of the last surviving attendees of Lincoln's assassination upon his death in 1932 at the age of 90. He was survived by five children, a sixth child, daughter Annie Leale, having died in 1915. Rebecca Copcutt Leale died in 1923. He was a member of the Protestant Episcopal Church of the Heavenly Rest, where funeral services were held on June 15, 1932. Burial followed in Oakland Cemetery.