May 30, 1776, John Adams to Samuel Cooper, “The Die is cast. We must all be soldiers and fight pro Aris et Focis. I hope there is not a Gentleman in the Massachusetts Bay, not even in the Town of Boston, who thinks himself too good to take his Firelock and his Spade. Such imminent Dangers level all Distinctions. You must before now, have seen Some important Resolutions of this Congress, as well as of Seperate Colonies. Before many Weeks you will see more.”
Pro Aris et Focis is a Latin motto meaning "For Our Altars and Our Hearths." For John Adams to Samuel Cooper, 30 May 1776, please consult Paul Herbert Smith, ed., Letters of Delegates to Congress, 1774-1789: Vol. 4: May 16-August 14, 1776 (Washington, D.C.: Library of Congress, 1979), pages 101-102.