Smokehouse Foundation.

ID: 5515 ~ Source: National Register Nomination Form. ~ Creator: Haley Schriber, John Milner Associates Preservation, Arlington, Virginia and John Twomey, U.S. Secret Service, Washington, D.C. ~ Date: July 2021.

This file appears in: United States Naval Observatory (USNO) Historic District: The USNO is the only American institution devoted to positional astronomy and timekeeping.

Brick foundation remnants of Building 151 (from nomination form).

This file appears in: United States Naval Observatory (USNO) Historic District: The USNO is the only American institution devoted to positional astronomy and timekeeping.

United States Naval Observatory (USNO) Historic District: The USNO is the only American institution devoted to positional astronomy and timekeeping.

By The DC Historic Sites team

The United States Naval Observatory (USNO) Historic District is encompassed by Observatory Circle and Massachusetts Avenue NW, and corresponds to a period of significance dating from 1887 to 1973. The…