Used primarily for diplomatic purposes, the Great Seal of the United States normally is affixed to commissions of diplomacy personnel, letters from the president to foreign leaders, and treaties. Its design was adopted by the Continental Congress on June 20, 1782, and by the U.S. Congress on September 15, 1789. William Barton, a Philadelphia lawyer, designed the obverse of the seal. Charles Thomson, secretary of the Continental Congress, designed the reverse. The obverse has a shield with 13 alternate red and white stripes superimposed on the breast of a bald eagle. In its right talon is an olive branch, for peace, and in its left talon are 13 arrows, symbolizing armed might. His beak holds a scroll inscribed with the motto, "E pluribus unum." Over the head of the eagle is a constellation of 13 stars against a blue sky, representing the 13 original states. The reverse of the seal contain an unfinished 13-step pyramid, topped with an eye, supposedly of God, within a triangle. Over the triangle are the words, "Annuit coeptis" (He has favored our undertakings). On the base of the pyramid are the Roman numerals MDCCLXXVI (1776), and below is a scroll with the motto, "Novus ordo seclorum" (A new order of the ages).