He lived most of his life in Winchester (where he settled in 1754) and served as a representative of that town in the Provincial Government which dealt with the launching of the Revolution. In 1776, he was appointed 1st Justice of the interior Court of Common Pleas of Cheshire County and held the post for many years even as he served in the Militia. During the Revolution, he fought at Ticonderoga and commanded the 13th and 6th New Hampshire Regiments. He was nominated as a delegate to the Continental Congress, but he did not accept.

The monument in the Claremont, New Hampshire Cemetery is inscribed as follows:
"In memory of the Hon. Sam'l Ashley, Esq. Blessed with good natural talents and an heart rightly to improve them, he in various departments of civil and military life exhibited a character honorable to himself and useful to others, having presided for several years in the lower court of this county. Probity and fidelity displayed the virtues of the patriot and Christian as well in public as in domestic life. The Small Pox put a period to his earthy course Feb 18, 1792, aged 71 years."