The Sauk and the Mesquakie are two closely associated but separate nations. Both oral histories tell of an original home on the Atlantic Ocean and a southwesterly migration via the St. Lawrence River. At the time of first contact with Europeans in 1666, both nations lived in what is now Wisconsin.

Although closely allied after 1734, the Mesquakie and the Sauk always maintained separate traditions and chiefs. The United States nevertheless considers them a single tribe and officially calls them the Sac and Fox. The word "Mesquakie" means red-earth people. The word "Sauk" means people of the outlet, and refers to their former home on Saginaw Bay (Michigan).

In 1766 French reports estimated Mesquakie numbers at approximately 5000 and the Sauk about 6500. Both nations lived in semi-permanent villages and sustained themselves through a combination of agriculture and hunting.

The Sauk and Mesquakie had three kinds of chiefs: civil, war, and ceremonial. Only the civil chief's position was hereditary. War and ceremonial chiefs were chosen based on proven ability and spiritual power. The members of a secret society, the Midewiwin, or Grand Medicine Society, healed the sick and enlisted supernatural guides to help ensure tribal welfare.

By the 19th century, both nations lived next to the Mississippi River on land between present-day Dubuque, Iowa, and St. Louis, Missouri. Over the first three decades of the 19th century, beginning with a controversial treaty in 1804, they ceded all of their lands to the U.S. government. With their land ceded, the government forcibly relocated them, first to Iowa, then Kansas, and finally to Oklahoma. In Kansas, major disagreements developed between the Sauk and the Mesquakie. Some of the Mesquakie joined the Kickapoo and moved to Mexico. By 1859, most of the remaining Mesquakie had returned to Iowa and purchased land near Tama, approximately 100 kilometres (62 miles) northeast of Des Moines.

Today the U.S. officially recognizes three Sac and Fox tribes: the 1100-member Sac and Fox Tribe of the Mississippi (located in Kansas), the 400-member Sac and Fox Tribe of Missouri (located in Iowa), and the 2200-member Sac and Fox Tribe of Indians (located in Oklahoma). The original 303,515-hectare (750,000 acres) reservation created for the Sauk and Mesquakie in Oklahoma is now a mere 405 hectares (1,000 acres). The Mesquakie who moved back to Iowa have fared better. The 32-hectare (80-acre) farm they originally purchased next to the Iowa River has grown to its present size of 1295 hectares (3200 acres).