This is the oldest known photo of the U.S. Department of State. The photo is from 1857 and shows the old State Department building, before it was located in Foggy Bottom, and even before it was located in the State, War, and Navy Building next to the White House.
The building below is the old North East Executive Building, near the White House. Read more about the building at the State Department’s Office of the Historian.
Source: Library of Congress