Amos Benton Hawley was born around 1835 in Vermont to Gordon and Loraine Hawley. His father was a farmer who owned $3,000 of real estate in 1850. Hawley grew up and attended school in New Haven, Vermont, and by 1850, he was working as a farmer. He married Henrietta Lattin in the late 1850s, and they had at least two children: Henry, born on September 6, 1860; and Mary, born around 1868.
Hawley enlisted in the Union army on September 20, 1861, and he mustered in as a private in Company D of the 5th Vermont Infantry on October 31. The regiment took part in the Siege of Yorktown, the Battle of Williamsburg, the Battle of Antietam, the Battle of Fredericksburg, the Battle of Chancellorsville, the Battle of Gettysburg, and the Overland Campaign. He was wounded in the Battle of the Wilderness on May 5, 1864, and he mustered out on October 15, 1864.
He returned to Vermont after the war, and by 1870, he was working in the dairy business in Cleveland, Ohio. The family moved to New Smyrna, Florida, in the 1870s, and he became a local post master in March 1879. By 1880, he was earning a living as a clerk in a grocery store. He applied for a federal pension in May 1880 and eventually secured one. He died in New Smyrna in 1892.