William A. Revell was born in Ireland, ca. 1842. He worked as a mechanic before enlisting in Company A, 13th New York Cavalry in November, 1862. In March, 1864, he was promoted and commissioned a second lieutenant. In 1864, he was promoted again, to first lieutenant and transferred to Company H of the same regiment. On March 30, 1865, he was promoted to captain and and apparently continued to serve as a captain when the 13th New York was combined with the 16th to form the 3rd New York Provisional Cavalry. The 3rd New York Provisional Cavalry was mustered out of service on September 21.

A William A. Revell, 38, appears in the 1880 census as a resident of New York City, working as a police sergeant and living with wife Anna, 42, a daughter and stepson; the Revells appear again in the 1900 census as residents of Brooklyn, the census record noting that the couple had been married for 36 years and had both immigrated to the United States in 1849. The census provides no occupation for William Revell, suggesting that he had retired by this time. The 1910 census shows Revell living in Watertown, Wisconsin with his second wife, Yetla. By the time he wrote the note in this collection, Revell seems to have been living in Oceanside, California. William A. Revell died in Sierra Madre, California, on May 7, 1924.