[3] These two parts are separated geographically as the Potomac Annex is at the top of the hill, while the E Street Complex is farther down.

Matthew Fontaine Maury was the first superintendent of the observatory, despite his interests lying more in oceanography and wind currents.

Under Maury, the observatory drafted charts on wind and ocean currents along with numerous volumes of sailing instructions.

In 1863, Abraham Lincoln visited the observatory at night to ask an astrological question to the astronomer on duty, Asaph Hall.

[5] The new telescope was purchased from a shop in Cambridgeport, Massachusetts and was delivered a full two years ahead of schedule.

It was the largest refracting telescope in the world at that time, and brought a lot of prestige to both the observatory and the United States.

[5] With Davis at the head, the observatory's exact time-keeping was used to standardize the time not only across Washington, D.C. but also around the country.

[10] The headquarters of the Office of Strategic Services was located in the E Street Complex until its dissolution in 1945, as was the superseding Central Intelligence Agency until 1961.

A joint venture consisting of the architectural firms of Goody, Clancy and the Louis Berger Group won a $2.5 million contract in January 2014 to begin planning the renovation of the buildings on the 11.8-acre (4.8 ha) Navy Hill campus.