The Pentagon was orginally built as a temporary solution to the War Departments critical shortage of space during the early years of World War II. The groundbreaking ceremony took place on September 11, 1941, and the dedication, nearly 16 months later. It cost approximately $83 million, consolodated 17 buildings of the War Dept, and returned its investment within seven years.
It is one of the world's largest office buildings, with 3,705,793 square feet, three times the floor space of the Empire State Building.
The Pentagon is virtually a city in itself. It employs 23,000 people, both military and civilian. More than 200,000 telephone calls are made daily and the Defense Post Office handles about 1,200,000 pieces of mail monthly.
The building alone is an extraordinary structure. It is still thought of as one of the most efficient office buildings in the world. Despite 17.5 miles of corridors it takes only seven minutes to walk between any two points in the building.