Empire of Commerce: The Closing of the Mississippi and the Opening of Atlantic Trade - Paperbackby Susan Gaunt Stearns (Author) A groundbreaking study situating the Mississippi River valley at the heart of the early American republic's political economy Shortly after the ratification of the US Constitution in 1789, twenty two year old Andrew Jackson pledged his allegiance to the king of Spain. Prior to the Louisiana Purchase, imperial control of the North American continent remained an open question. Spain controlled the Mississippi River,