Constructed in 1822, the building is a combination of Federal and Second Empire architecture. It originally served as the residence of the second Sargent at Arms of the Senate, General Mountjoy Bayly. From 1929 until 1947, it was the residence of Senator Hiram Johnson, former governor of California and a founder of the Progressive Party. The building is designated as a National Historic Landmark and contributing property to the Capitol Hill Historic District. The current owner of the building is the American Civil Liberties Union (ACLU).
Hiram W. Johnson lived in this 2%-story, mansard-roofed, white painted,stuccoed, brick house from 1929 until his death in 194 According to the staff of the California State Historic Officer, there are no remaining Johnson residences in California. Besides this structure, the only other known extant Johnson dwelling is Riversdale (Calvert Mansion) in Riverdale, Md., where he lived for several years before moving here.
National Register of Historic Places: July 20, 1973
National Historic Landmark: December 8, 1976