The White House to Treasury Building tunnel is a subterranean structure in Washington, D.C. that connects a sub-basement of the East Wing of the White House to the areaway which surrounds the United States Treasury Building. It was originally constructed in 1941 to allow the evacuation of the president from the White House to underground vaults inside the Treasury in the event of an emergency. History Background The idea of using the sturdy Treasury Building as a refuge of last resort has some precedent. Immediately after the Battle of Fort Sumter in 1861, there was concern that an attack on Washington was imminent. General Winfield Scott had the building readied to be used as a "last stand" by the federal government in the event the capital city was overrun. The exterior of the building was ringed with sandbags and soldiers, and inside corridors and hallways leading to the underground vaults were barricaded "floor to ceiling". In the event of an unstoppable assault against the capital, plans had been drawn up for surviving U.S. Army forces to fight from three centers of final resistance with the Treasury Building as the "citadel" of the third. Under the army's plans, troops assigned to defend the White House would fight a delaying action in President's Park to cover the evacuation of Abraham Lincoln into the Treasury vaults. Early tunnel rumors In the early 1930s, a decade before the tunnel was actually constructed, a rumor circulated that such a passageway already existed connecting the White House to the Treasury Building. According to one account, the rumor started as a joke among journalists covering the White House, but gained serious traction, with some accounts even suggesting that Secretary Of The Treasury Ogden L. Mills was secretly accessing the White House via the purported passage to meet with President Herbert Hoover. World War II Shortly after the Pearl Harbor attack, in December 1941, construction began on a hardened bunker to the east of the White House grounds that would provide a secure refuge for the president in the event of an air raid against the capital city. To hide construction of the facility from the public, the East Wing was built on top of the bunker. This facility would later become the Presidential Emergency Operations Center. As a stop-gap measure, the fortified vaults in the basement of the United States Treasury Building were converted into living quarters