Engineer (1890-1974) known for his pivotal role in the development of the atomic bomb as a primary organizer of the Manhattan Project. Two items signed by Vannevar Bush: a glossy 8 x 10 portrait by Hessler Studio, signed in fountain pen, with the reverse bearing a studio credit stamp and typed collector's notation indicating that it was received in 1951; and a pamphlet entitled "The Atomic Bomb and the Defense of the Free World," given as an address by Bush for the Committee on the Present Danger on March 4, 1951, 11 pages, 4 x 8.25, signed on the front in fountain pen. In very good to fine condition, with scattered creasing to the photo, heaviest in the upper right corner. Accompanied by the original mailing envelope for the pamphlet.