The PMA used a variety of exhibition spaces until 1908; that year Margaret Jane Mussey Sweat bequeathed her three-story mansion, now known as the McLellan House, and sufficient funds to create a gallery in memory of her late husband, Lorenzo De Medici Sweat, who was a U.S. Representative. Noted New England architect John Calvin Stevens designed the L. D. M. Sweat Memorial Galleries, which opened to the public in 1911.