The US Naval Observatory was established on Dec 6, 1830, as the Depot of Charts and Instruments under the command of LT Louis Goldsborough. Its function was to maintain, repair and rate navigational instruments and had an annual budget of $330. Its mission expanded in 1842 to include its function as the national observatory, and moved to its current location in 1893. (Back then, it was out in the boondocks and away from the lights of the city.)
Navigational instruments include chronometers, necessary for determining longitude, which is why the Observatory maintains time for the military.
Happy 183rd birthday.