 Slavery in the Wisconsin Territory (some of which, including Fort Snelling, was part of the Louisiana Purchase) was prohibited by the United States Congress under the Missouri Compromise.During his stay at Fort Snelling, Scott married Harriet Robinson in a civil ceremony by Harriet's owner, Major Lawrence Taliaferro, a justice of the peace who was also an Indian agent.The ceremony would have been unnecessary had Dred Scott been a slave, as slave marriages had no recognition in the law.