<P> The Emancipation Proclamation was an executive order, itself a rather unusual thing in those days . Executive orders are simply presidential directives issued to agents of the executive department by its boss . </P> <P> Until the early 1900s, executive orders went mostly unannounced and undocumented and seen only by the agencies to which they were directed . That changed when the Department of State instituted a numbering scheme in 1907, starting retroactively with United States Executive Order 1 issued on October 20, 1862, by President Abraham Lincoln . The documents that later came to be known as "executive orders" apparently gained their name from this order issued by Lincoln, which was captioned "Executive Order Establishing a Provisional Court in Louisiana". This court functioned during the military occupation of Louisiana during the American Civil War, and Lincoln also used Executive Order 1 to appoint Charles A. Peabody as judge, and to designate the salaries of the court's officers . </P> <P> President Truman's Executive Order 10340 in Youngstown Sheet & Tube Co. v. Sawyer, 343 US 579 (1952) placed all steel mills in the country under federal control . This was found invalid because it attempted to make law, rather than clarify or act to further a law put forth by the Congress or the Constitution . Presidents since this decision have generally been careful to cite which specific laws they are acting under when issuing new executive orders . Likewise, when presidents believe their authority for issuing an executive order stems from within the powers outlined in the Constitution, the order will simply proclaim "under the authority vested in me by the Constitution" instead . </P> <P> Wars have been fought upon executive order, including the 1999 Kosovo War during Bill Clinton's second term in office . However, all such wars have had authorizing resolutions from Congress . The extent to which the president may exercise military power independently of Congress and the scope of the War Powers Resolution remain unresolved constitutional issues, although all presidents since its passage have complied with the terms of the resolution while maintaining that they are not constitutionally required to do so . </P>

How can a president sign an executive order