Augustus Hill Garland was born in Covington, Tennessee on June 11, 1832. The next year, his parents moved their family to Lost Prairie, Arkansas. He attended college in Kentucky at St. Mary's College and then St. Joseph's College from which he graduated in 1849. Garland moved to Washington, Arkansas to study law and was admitted to the bar in 1853, starting his law practice with his stepfather.

Garland moved his family to Little Rock in June 1856, becoming law partner to Ebenezer Cummins. When Cummins died, Garland took over the whole practice. Garland became politically active in the 1850s and held political positions during the American Civil War. He was first a representative of Pulaski County at the 1861 secession convention in Little Rock, initially opposing secession. He was later both a representative and senator for Arkansas in the Confederate States Congress.

Garland was plaintiff in the case Ex parte Garland, in which the Supreme Court ruled that Garland, and others, would not have to take a loyalty oath to the United States due to receiving a pardon from President Johnson. Garland would go on to serve as the eleventh governor of Arkansas, from 1874 to 1877, as United States Senator for the state from 1877 to 1885, and lastly served as United States Attorney General from 1885 to 1889. After this, Garland continued practicing law in Washington, D. C. and published several books on law. Garland passed away in Washington, D. C. on January 26, 1899.