The mansion was the home of Margaret Jane Mussey Sweat (1823-1908) (site SA01), a writer, literary and art critic, and world traveler, who founded the first public art museum in Maine. She was brought up in The Elms at the corner of Danforth and High Streets (site S21). She and her husband, Lorendo de Medici Sweat, a Portland lawyer and representative to Congress, lived in Washington, D.C., in the winter and used the Spring Street house as their summer home. The building was bequeathed to the Portland Society of Art upon Margaret Sweat's death, together with a building erected as an art museum and memorial to her husband. An authority on George Sand and Charlotte Bronte, she published accounts of her travels and one novel, Ethel's Love Life, which illuminates nineteenth-century women's romantic friendships. The mansion is connected to the Portland Museum of Art at the rear and houses museum exhibits.