What is the capital of the United States?

The capital of the United States is Washington, D.C. This city was established as the nation's capital in 1800 and was selected due to its location between the northern and southern states, making it a neutral ground during a time of regional tensions. Washington, D.C. houses the federal government, including the President's residence, the White House, and the Capitol building, where Congress meets.

Unlike New York City, which was the temporary capital before Washington, D.C., it is not the political center of the nation today. Los Angeles and Chicago, while being major cities, are not the capital and do not serve the same political function as Washington, D.C. Thus, this city's unique role in American governance and its historical significance as the capital substantiate it as the correct answer.