He was an ardent leader of the opposition to the Stamp Act, advocating even then a separation of the colonies from the mother country; and in the Continental Congress of 1774 he discussed the situation on the basis of inalienable rights and liberties, and urged an immediate attack on General Thomas Gage, that he might be defeated before receiving reinforcements.
In1861-1863he was a member of the national House of Representatives, where, while advocating the prosecution of the war, he opposed such radical measures as the division of Virginia, the enlistment of slaves and the Conscription Acts.
His pamphlet, War and Peace: the Evils of the First with a Plan for Securing the Last, advocating international arbitration, was published by the English Peace Society in 1842, and is said to have contributed to the promulgation, by the powers signing the Treaty of Paris in 1856, of a protocol expressing the wish that nations, before resorting to arms, should have recourse to the good offices of a friendly power.
He appears to have anticipated Wycliffe in advocating the subordination of the clergy to the king.
On his journey to Great Britain he made a speech in New York, May 31 1918, advocating the application of the Monroe doctrine to the South Pacific islands in the interests of Australia, and at the Paris Peace Conference of 1919, where he was the Australian representative, he objected to any authority over ex-German territory in these islands being granted to the League of Nations.