Amos moved from Woodbury, CT to Salisbury, CT and then to Richmond, VT before the Revolutionary War. The first settlements within the limits of the town of Richmond, VT were begun by Amos Brownson and John Chamberlain with their families in 1775 on what is called Richmond Flats on the south side of the Winooski River. In the fall of 1775 they abandoned the township as it was so unprotected from both the Indians and the British. They returned to Richmond at the end of the Revolutionary War accompanied by Asa and Joel Brownson.

Amos spent 11 days serving in the alarm for the relief of Fort William Henry during the French and Indian War as written in Vol. 1, pg. 204. This volumn also indicates that Amos served in a unit of the Green Mountain Boys: Capt. Samuel Bellow's Co. of Salisbury, Goodrich's Regt. of Foot. He served in the campaign against Crown Point from Aug 25 to Dec 7, 1755. In 1788, 1791 and 1793, Amos represented Williston, VT and in 1794 he represented Huntington. He was a member of the VT State Constitutional Convention of 1791 and 1793 from Huntington.

It is said that Amos was much over six foot tall and slightly stooped from hard work and rheumatism.