Question

What is the capital of the United States?

Answer 1

The Capital City is Washington DC.

The Capital Building is the large building in the Capital City where
the US Congress (the Senate and the House of Representatives)
convenes.  That makes it the headquarters of the Legislative Branch
of the US government. 

Answer 2

The United States of America is located in North America is located in North America. It's the third largest country in the world and its capital is Washington, D.C.