United States Naval Observatory (Vice President's residence)

The United States Naval Observatory (USNO) was established as a federal scientific agency in 1830 and relocated to its current Northwest Washington campus in 1893. The property at Number One Observatory Circle has served as the official residence of the Vice President of the United States since 1974. The USNO continues to operate astronomical research facilities and maintains the master clock and timekeeping services used for precise naval and national timing. The campus combines residential, administrative, and scientific functions on a gated site north of Massachusetts Avenue.