Today in history: On June 18, 1812, the War of 1812 began as the United States Congress approved, and President James Madison signed, a declaration of war against Britain. Also on this date: In 1778, American forces entered Philadelphia as the British withdrew during the Revolutionary War. In 1815, Napoleon Bonaparte was defeated in the Battle of Waterloo as British and Prussian troops defeated the French Imperial Army in Belgium. In 1979, President Jimmy Carter and Soviet President Leonid