Amos was a son of Ebenezer and Mehitabel (Miller) Barnes of Middletown. He was born March 25, 1732, and baptized the next day.
Amos first married widow Sarah Crowel at Middletown, on May 17, 1764. After her death in July 1770, he married Abigail Brooks. The ceremony took place in Middletown, on May 2, 1771.
The couple had two daughters, Rhoda (b. 1772, she married Remembrance Simmons Keeney) and Abigail (b. 1775, she married Capt. Lathrop Lee). Amos and Abigail Barnes were mentioned in her father's will of 1793, as well as in land deeds of the early 1800s in Middletown.
Amos died Feb. 20, 1814, at Middletown. Sarah survived him, until her death in 1816.