I INTRODUCTION  Washington, D.C., city and district, capital of the United States of America. The city of Washington has the same boundaries as the District of Columbia (D.C.), a federal territory established in 1790 as the site of the new nation’s permanent capital. Named after the first U.S. president, George Washington, the city has served since 1800 as the seat of federal government. It is also the heart of a dynamic metropolitan region. During the 20th century, the Washington, D.C., metropolitan area grew rapidly as the responsibilities of national government increased, both at home and throughout the world.
The city is located at the confluence of the Potomac and Anacostia rivers and is flanked on the north, east, and southeast by Maryland and on the southwest by Virginia. Although the city has retained some aspects of its Southern origin, it has assumed a much more cosmopolitan character. At the same time, the city struggles with social and economic disparity, and a number of its residential neighborhoods suffer from poverty and crime. Washington’s climate is hot and humid in the summer and cold and damp in the winter. The average daily temperature range is -3° C (27° F) to 8° C (46° F) in January and 22° C (72° F) to 31° C (88° F) in July. The city averages 98 cm (39 in) of precipitation per year.
II WASHINGTON AND ITS METROPOLITAN AREA   A The Outline of the City  Designated to serve as the permanent seat of the federal government beginning in 1800, the District of Columbia was named for Christopher Columbus. It was created from land ceded by the states of Virginia and Maryland, and it incorporated the existing seaport towns of Alexandria, Virginia, and Georgetown, Maryland. The district was originally 259 sq km (100 sq mi), or 10 miles square, as established under the Residence Act of 1790. The central town site was laid out by French architect Pierre Charles L’Enfant in 1791. The remaining land was an open area stretching north to the border with M