The 1904 Louisiana Purchase Exposition closed with a surplus, and the Exposition Company — with the approval of Congress and under the authority of the City of St. Louis — put the money toward a permanent memorial to Thomas Jefferson on the site of the fair's main entrance. Isaac S. Taylor, the fair's Director of Works, designed the building; Karl Bitter, who led the fair's sculpture program, created the seated Jefferson in the loggia; James Stewart & Co. built it. Dedicated on April 30, 1913, and accepted by Mayor Henry Kiel, it was the first national memorial to Jefferson, predating the memorial in Washington by three decades. The fair's profits also paid for the World's Fair Pavilion, completed the same year. The building became home to the Missouri Historical Society, founded in 1866, and has operated as the Missouri History Museum ever since. In 1988 the museum joined the Metropolitan Zoological Park and Museum District, making admission free through public subsidy. In 2000 the Emerson Center addition, designed by Hellmuth, Obata & Kassabaum, added exhibition space, an auditorium, and classrooms behind a ground-to-roof glass facade on the south side. The original building is City Landmark #107.
