What is behind the U.S. Capitol building’s small doors?
Throughout the U.S. Capitol Building, visitors and staff often pause to imagine what is behind the building's smallest doors. Their guesses are as varied as the architectural details that encompass the Capitol campus.
The correct explanation for their existence begins with a fire on Christmas Eve 1851. At that time the Library of Congress was housed in the Capitol Building. That morning as John Jones, a guard, was walking on the Capitol Grounds he noticed a flicker through the Library windows. Jones had no key to the room, so he was forced to break the door down. Once inside, he discovered a small fire. Water was not readily available in the building, so Jones had to run downstairs to find some. By the time he returned, the fire had spread throughout the two-story Library. Seven fire stations responded to the alarms. Firefighters worked all day and night and into Christmas morning to extinguish the flames.
The fire devastated the Library's collection: thirty-five thousand volumes were destroyed. Approximately two-thirds of the books purchased from Thomas Jefferson were gone. Manuscripts, maps and other artwork had been consumed by the fire, which was later determined to have been caused by a spark from the fireplace in the room below the Library.
During the investigation, Jones testified that the fire could have been easily extinguished had there been water nearby. The fear of future fires motivated Congress to fund a critically needed reliable water supply for Washington, D.C.
Captain Montgomery C. Meigs of the U.S. Army Corps of Engineers was assigned by the War Department to manage the project. Meigs had a remarkable career. He helped build many D.C. landmarks, including Arlington National Cemetery, the Capitol Building extension and the modern Dome of the Capitol Building. Arguably his most significant engineering achievement was the Washington Aqueduct. The elaborate system brought fresh water from the Potomac River at Great Falls into the federal city and into the pipes hidden behind the Capitol's small doors.
These small doors and the water sources they housed, found in several places in the Capitol Building, were multipurpose. They stood ready to provide water to prevent any future fire from spreading, but they also ensured the mud tracked in from Washington's dirt streets and footpaths could be easily cleaned from the Capitol's floors. That is why the doors stand only about 30 inches tall: they conceal low, shallow closets where workers filled pails of water to mop the floors.
Over the years Meigs' water system has undergone many upgrades, but it still carries water into the city today. The Capitol, too, has also undergone many renovations over the years, including more accessible water fixtures and modern fire-suppression systems. Although the small doors are no longer necessary for their original purpose, they are still very much a part of the Capitol as visitors stop to admire their tiny size and imagine what could possibly be behind them.