The cornerstone is laid for a presidential residence in the newly designated capital city of Washington. In 1800, President John Adams became the first president to reside in the executive mansion, which soon became known as the "White House" because its white-gray Virginia freestone contrasted strikingly with the red brick of nearby buildings. The city of Washington was created to replace Philadelphia as the nation's capital because of its geographical position in the center of the existing new republic. The states of Maryland and Virginia ceded land around the Potomac River to form the District of Columbia, and work began on Washington in 1791. French architect Charles L'Enfant designed the area's radical layout, full of dozens of circles, crisscross avenues, and plentiful parks. In 1792, work began on the neoclassical White House building at 1600 Pennsylvania Avenue under the guidance of Irish American architect James Hoban, whose design was influenced by Leinster House in Dublin and by a building sketch in James Gibbs' Book of Architecture. President George Washington chose the site.