Bancroft Hall was designed in the Beaux-Arts style with its mansard roof and dormer windows by architect Ernest Flagg and its central rotunda and first two wings were built in 1901–06. Over the intervening years it has been expanded to encompass eight wings of five stories ("decks") each numbered 0–4. The original two wings (1906) are now the 3rd and 4th wings; the next pair, added in the 1917, are now the 1st and 2nd wings; a pair added in 1939 became the 5th and 6th wings; and a final pair were added in the 1961 as the 7th and 8th wings. The 3rd wing was built over the remains of the old Fort Severn.