Augustus was born in 1840 in Ireland, and very little is known about his life. He enlisted in the 16th US Infantry, and it was his actions as a Sergeant Major while in Tennessee and Georgia that would later earn him the Medal of Honor. The citation reads:

Gallantry in various actions during the rebellion.

Augustus received the Medal of Honor on the 28th of February 1870, and the following year, on the 3rd of August 1871, Augustus Barry died. He is buried in the Cold Harbor National Cemetery in Mechanicsville, Virginia: Section A, plot 309.