Allen White Tiffany appears to have been born in Peru, Berkshire County, Massachusetts on 8 July 1827, the son of Giles Hamlin and Anna Tiffany. He studied law, was admitted to the bar and practiced in Dixon, Illinois. He married Eliza Hale Pierce of Burlington, New York, in 1854. In 1856, he moved to Carver County, Minnesota Territory. In 1860, he appears as a farmer in Florence Township, Carver County with his wife Eliza and children Mary and George W. 22 August 1862, he enlisted as a private in Company H of the Ninth Minnesota Infantry Regiment. During the war he was promoted to Sergeant and later Second Lieutenant. 10 June 1864, he was captured at Guntown, Mississippi, and appears to have spent some time as a prisoner of war in the Andersonville Prison. In August and September he was a prisoner of war in Charleston, South Carolina. He was mustered out at Fort Snelling, 24 August 1865.

He returned to Minnesota, where he appears in the 1865 census of Young America Township, Carver County with his wife and two children. Tiffany was active in local government, serving as chairman of the township board of supervisors and a member of the Carver County Board of Commissioners. In 1880 he was elected to the Minnesota State Senate from District 33, serving from 1881 to January 1, 1883. He was a member, and in 1888 commander, of the John C. Becht post, Grand Army of the Republic, at Young America.

At some point after 1888, the Tiffany family moved to Washington state where Allen received pension certificate 10000235 for service in the Civil War on 5 February 1895. He appears in the West Ferndale Precinct of Whatcom County, Washington, in the 1900 census. He died at his farm home in Whatcom County, Washington in 1903. His wife Eliza received her widow's pension (certificate 654006) on 2 April 1903. Eliza Tiffany died in Ferndale, 14 November 1910. He had five children, two of whom died in infancy.