After the U.S.–Dakota War of 1862 — the starvation-driven uprising in Minnesota — military commissions tried 392 Dakota men in proceedings lasting minutes each, without counsel, and condemned 303 to death. President Lincoln commuted most, but on December 26, 1862, thirty-eight Dakota men were hanged together at Mankato: the largest mass execution in American history, carried out the week of the Emancipation Proclamation.

The commuted and convicted — some 265 men — were shipped to a prison camp at Davenport, Iowa, where dozens died of disease over three years, while sixteen hundred Dakota women, children, and elders were interned at Fort Snelling and then exiled from Minnesota by act of Congress. The Dakota 38+2 memorial ride each December marks the case at the foundation of Indigenous political imprisonment.