The Pembina Region ( ), also referred to as the Pembina District and Pembina Department, is the historic name of an unorganized territory of land that was ceded to the United States. The area included parts of what became North Dakota and a portion of central eastern to northeastern South Dakota. The eastern boundary was the Red River and included the Pembina River area. The region was formerly part of British Rupert's Land and the Red River Colony (controlled by the Hudson's Bay Company), that encompassed an area then known as the Assiniboia District, from 1763 to the signing of the Treaty of 1818. The treaty transferred the region that was south of the 49th parallel from the British to the United States. The area was referred to as the Pembina Territory after the U.S. army explorer Stephen Harriman Long made surveys during the 1823 expedition to the Red River of the North and placed an International boundary marker north of Pembina clearly defining the border between the United States and British North America. From 1818 until 1823 Pembina was considered (by both countries) to be within the boundary of the United Kingdom. Territorial status as Pembina never reached fruition because of area political in-fighting. Several attempts at formal recognition and naming failed to pass Congress. In 1849 Father Georges-Antoine Belcourt described the area, referred to as Pembina district or department, as a country about 400 miles from north to south and more than five hundred miles from east to west. The region was considered unorganized from 1818 until March 3, 1849, when the region was absorbed into the Territory of Minnesota. When Minnesota became a state on May 11, 1858, and the boundary was set at the Red River, the region became unorganized. The remaining region that failed to make territory status was finally absorbed into the states of North and South Dakota. History Several events shaped the area of the Pembina Region within the United States. The Louisiana Purchase (1803) included almost all of current South Dakota, the southern half and some of the north-central part of Minnesota, that became the District of Louisiana. The area was populated mostly with Chippewa (Ojibwe), fur trappers, and Métis, that was a mixture of French and Indian. After trying unsuccessfully to get a British land grant, because the land was under a monopoly of the Hudson's Bay Company (HBC), Thomas Douglas,