The following year the Revolutionary War broke out and Alfred served as a captain in a North Carolina regiment. The war was costly to the Moore family. British troops captured the Moore plantation and burned the family home, and Alfred’s father, brother, and an uncle were among those who served and died.

At the end of the war Alfred was elected to North Carolina’s General Assembly, which eventually elected him to serve as Attorney General; a position he held from 1782 to 1791. Moore was an ardent Federalist favoring a strong national government and he took a leading role in securing North Carolina’s ratification of the United States Constitution after the state had initially rejected it in 1788. After North Carolina’s admission to the Union as the 12th state, Moore worked as a lawyer, was active in political affairs, and served as a judge. He served in the North Carolina State legislature, but lost by a single vote in his run for the United States Senate.

In 1799, James Iredell, a North Carolinian and a member of the U.S. Supreme Court, passed away while serving on the bench. President John Adams responded to the vacancy by nominating Alfred Moore, at 4 feet 5 inches tall among the most diminutive justices ever to sit on the Supreme Court. Due to poor health, Moore’s contribution to the court was nearly as short as he was. In his five years of service he wrote only one opinion, upholding a conclusion that France was an enemy in the undeclared war of 1798-99.