Williams would come to hold a number of local offices, including as town clerk, and then was elected to the Connecticut lower house. He was appointed as a member of the Continental Congress in 1776 and again in 1783. He signed both the Declaration of Independence and Articles of Confederation. He was also a delegate at the Connecticut Convention in 1788 and voted to ratify the Constitution. During these years he also served as judge of the Windham County Court and judge of probate for the Windham District. He died in 1811.