Wahpeton is a city in Richland County, in southeastern North Dakota, United States. It is located along the Bois de Sioux River at its confluence with the Otter Tail River, forming the Red River of the North. Wahpeton is the county seat of Richland County. The U.S. Census Bureau estimated the city's 2015 population was 7,899.Wahpeton was founded in 1869 and is the principal city of the Wahpeton Micropolitan Statistical Area, which includes all of Richland County, North Dakota and Wilkin County, Minnesota. Wahpeton's twin city is Breckenridge, Minnesota, located to the east on the other side of the river. The Bois de Sioux River and the Otter Tail River join at Wahpeton and Breckenridge to form the Red River of the North.The North Dakota State College of Science is located in Wahpeton. The local newspaper is the Wahpeton Daily News.HistoryThe first European explorer in the area was Jonathan Carver in 1767. He explored and mapped the Northwest at the request of Major Robert Rogers, commander of Fort Michilimackinac. This British fort at Mackinaw City, Michigan, protected the passage between Lake Michigan and Lake Huron of the Great Lakes. In 1763 the British had extended their reach in Canada after defeating the French in the Seven Years' War.