In 1824, the U.S. Army consisted of the Regular Army, volunteers raised by the States as authorized and funded by Congress and directed by the President and the militia called into Federal service under Section 8, Article I of the Constitution to oppose foreign invasion or internal armed insurrection. In general, it was accepted that the militia could not serve outside the country, a viewpoint later confirmed by a Supreme Court ruling. (Notice in the right hand illustrations, the artillery unit marching with muskets) File:339 335 Urwin.jpg