The East Wing, which contains additional office space, was added to the White House in 1942. Among its uses, the East Wing has intermittently housed the offices and staff of the First Lady, and the White House Social Office. Rosalynn Carter, in 1977, was the first to place her personal office in the East Wing and to formally call it the "Office of the First Lady." The East Wing was built during World War II in order to hide the construction of an underground bunker to be used in emergencies. The bunker has come to be known as the Presidential Emergency Operations Center.