In June, 1936 the museum first opened under the direction of the Daniel Newcomb Chapter of Daughters of the American Revolution in Yankton, South Dakota. The Museum was located in the former Dakota Territorial Council Hall - which had been relocated in present-day Riverside Park.
In 1953, the hall and museum were moved to West Side Park.
In 1961 the Yankton County Historical Society was officially formed and took over care of the Museum.
The 1971 a new and larger building was built next to the old council building. For more than 30 years the Museum has called this building home. The former Dakota Territorial Council building remained as extra exhibit space, and many additional outside buildings have been added, including the Gunderson
Yankton's First Museum was located down by the river, not far from present-day Riverside Park.
In 1953 the structure was moved to West Side Park and re-opened to the public. Soon after it was decided that the space was too small for a museum. Changes would be coming.
In December 2018 the Mead Cultural Education Center was opened to the public.
New exhibits will be added to the museum yearly. The Childrens Transportation museum is the first of its kind in the region.
Located next to original museum, this larger facility opened to the public in 1971.
The Yankton County Historical Society, through the Dakota Territorial Museum, exists to preserve, protect, interpret, and educate the public about the heritage and development of the city and county of Yankton, and the Dakota Territory.
Rural School House, Hovden Cabin and the Burlington Northern Caboose.
2012, the YCHS Board of Directors accepted the task of saving a building located on the north edge of Yankton that was part of the former Dakota Hospital for the Insane campus. The Mead Building has been a multi-year, multi-million dollar venture that reopened in 2018 as the Mead Cultural Education Center (MCEC). The MCEC will be the home of the Yankton County Historical Society, Dakota Territorial Museum, and is the future home of the Yankton College Alumni offices.
The Dakota Territorial Museum focuses on the development of the Dakota Territory (1861-1889) and also Yankton County, South Dakota (1889-present). Yankton was the first capital of the Dakota Territory.