Representing Virginia at the Continental Congress
He was educated at William and Mary College. In 1760 he was appointed to represent King William county in the Virginia House of Burgesses. He was in attendance 1765, when Patrick Henry's Stamp Act resolutions agitated the Assembly. In 1769 he joined the "radical" faction of the Burgesses in support of Virginia's sole right to tax inhabitants. When the house was dissolved in 1774 he joined the patriot's Committee of Safety in Virginia, and represented his county in the Virginia Convention. In 1775, upon the sudden death of Peyton Randolph, Braxton was selected to assume his place in the Continental Congress. He attended two years, after which he returned to Virginia to continue service to the House of Burgesses.
During the War, he had loaned £10,000 sterling to support the revolutionary cause. He had also used his wealth to sponsor shipping, but the British captured most of his vessels and ravaged some of his plantations and landholdings, the losses from which eventually resulted in debt. He never recovered, and, in 1786, was forced to leave his inherited country estate for simple quarters in Richmond. He died at age 61 and was buried in the cemetery next to his estate Chericoke.