The corridors are lined with cast iron pilasters and columns, black and white limestone and marble floors, and the ceilings have shallow arched vaults
that alternate in narrow and wide bays. These are seven levels of corridors in the building, which equal 1 1/4 miles in length. The paint colors have
been restored to their original appearance when each wing was completed. The corridor
length on each floor is one quarter of a mile. All together, the seven levels of the corridor total one and three quarters of a mile.
Corridor column at
center stair, 1991. EOP Preservation Office.
When the building was first occupied, messengers were stationed outside many of the offices to convey important documents and messages between
the staff, and to other departments across town. The messengers were gradually replaced as telephones become widely used and available.
Between 1888 and 1902, soldiers in town for inaugural activities were quartered in the corridors. To make the top floor as comfortable as possible in
1893, the building superintendant put gun racks in all corridors, and covered the floors with three inches of sawdust (Washington Post, Feb. 10, 1893,
Corridor pilaster capital, 1991. EOP Preservation Office.