Emanuel Gottlieb Leutze, Westward the Course of Empire Takes Its Way (mural study for the United States Capitol building), 1861, oil on canvas, 84.5 x 110.1 cm (Smithsonian American Art Museum, Bequest of Sara Carr Upton, 1931.6.1)
Additional resources:
TEDEd lesson: Reading a History Painting (The Smithsonian American Art Museum)
See Leutze’s mural at the U.S. Capitol