<p>This category is devoted to sites for and about the United States of America, a federal democratic republic in North America which declared independence from Britain July 4, 1776 and ratified its present Constitution September 20, 1787. Its capital city is Washington, in the District of Columbia (DC).</p> <p>The US occupies 9,629,091 sq km in 50 states plus DC; its possessions include a variety of Pacific, Atlantic, and Caribbean islands. It is a preeminent nation-state in terms of economic power, diversity, and technology; population and land area; and military strength.</p>