Map - Dakota County, Minnesota (Dakota County)

Dakota County is the third-most populous county in the U.S. state of Minnesota, located in the east central portion of the state. As of the 2020 census, the population was 439,882. The population of Dakota County was estimated to be 442,038 in 2021. The county seat is Hastings. Dakota County is named for the Dakota Sioux tribal bands who inhabited the area. The name is recorded as "Dahkotah" in the United States Census records until 1851. Dakota County is included in the Minneapolis–St. Paul–Bloomington, MN–WI Metropolitan Statistical Area, the sixteenth largest metropolitan area in the United States with about 3.64 million residents. The largest city in Dakota County is the city of Lakeville, the eleventh-largest city in Minnesota and sixth-largest Twin Cities suburb. The county is bordered by the Minnesota and Mississippi Rivers on the north, and the state of Wisconsin on the east.

The county was the site of historical events at Mendota that defined the state's future, including providing materials for the construction of Fort Snelling across the river and the signing of the Treaty of Traverse des Sioux which ceded land from the native Dakota nation for the Minnesota Territory. The county's history was initially tied to the confluence of the Mississippi and Minnesota Rivers, both strategically important for United States expansion and as the convergence of the Dakota and Ojibwe nations who regarded the site as sacred. Influence shifted westward during the post-World War II settlement boom when Interstate 35 connected the western half of the county to Minneapolis and Saint Paul and bedroom communities grew. Most work outside the county but like many metro counties, Dakota continues to absorb industry and jobs from the core cities.

In the 1600s, Mdewakanton Dakota fled their ancestral home of Mille Lacs Lake in northern Minnesota in response to westward expansion of the Ojibwe nation. According to Dakota tradition, their ancestors pushed out the Iowa who were found settled at the mouth of the Minnesota River. In 1680, the Mdewakanton Dakota were contacted by French explorer Daniel Greysolon, Sieur du Lhut, and the Mendota (mdo-TE) band of the Mdewakanton south of the Minnesota River were contacted by Joseph Nicollet in the 18th century. While Taoyateduta (a.k.a. Little Crow) led the Mendota in northern Dakota County, upstream to the southwest, Chief Black Dog established his village of 600 people around 1750 at the isthmus between Black Dog Lake (which is named after him) and the Minnesota River, near the present site of the Black Dog Power Plant.

Following the published expeditions of explorers, in 1805, Zebulon Pike negotiated for military territory with the Mendota band which included land in Dakota County at the Mississippi River confluences with the Minnesota and St. Croix Rivers. In 1819, on what is now Picnic Island on the south bank of the Minnesota River, Colonel Henry Leavenworth built a stockade fort called "St. Peter's Cantonment" or "New Hope," where materials were assembled for the construction of Fort Snelling to be built on the bluff on the north bank. Permanent settlement on the island was impossible due to annual flooding. Alexis Bailey built some log buildings nearby to trade in furs in 1826. Henry Hastings Sibley later built the first stone house in Minnesota in 1836, overlooking Fort Snelling. Sibley was a partner in the American Fur Company, and considerable fur trade occurred at Mendota due to the accessibility of the confluence.

Ongoing United States expansion into the then "Northwest Territory" led to government purchase of land from the Dakota people (the Mdewakanton, Wahpekute, Wahpeton, and Sisseton bands) via the Treaty of St. Peters, the Treaty of Traverse des Sioux, and the Treaty of Mendota in 1851. After the Minnesota Territory was established in 1849, Dakotah County (later Dakota County) spanned from the Mississippi River to the Missouri River. By the time Minnesota achieved statehood in 1858, power and influence had shifted from Mendota, across the rivers to Saint Paul and Minneapolis.