Richard Delafield was a United States Army officer for 52 years. He served as superintendent of the United States Military Academy for a total of 12 years. At the start of the American Civil War, then Colonel Delafield helped equip and send volunteers from New York to the Union Army. He also was in command of defenses around New York harbor from 1861 to April 1864. On April 22, 1864, he was promoted to brigadier general in the Regular Army of the United States and Chief of Engineers. On March 8, 1866, President Andrew Johnson nominated Delafield for appointment to the grade of brevet major general in the Regular Army, to rank from March 13, 1865, and the United States Senate confirmed the appointment on May 4, 1866, reconfirmed due to a technicality on July 14, 1866. He retired from the US Army on August 8, 1866. He later served on two commissions relating to improvements to Boston Harbor and to lighthouses. He also served as a regent of the Smithsonian Institution.

Edward Delafield was an American physician, primarily known as an ophthalmologist, but also for his work in obstetrics and gynaecology. He was the co-founder of the New York Eye Infirmary and the first president of the American Ophthalmological Society. From 1858 until his death he was the president of the College of Physicians and Surgeons in New York City. His son, Francis Delafield, also became a prominent physician.