Yuma Crossing
Immediately after the Mexican–American War in 1848, the U.S. Army built Fort Yuma here to protect travelers from Indians raiding the area. It was the center point of conflict in the Yuma War of 1850–53. From 1864–1890, the fort and nearby facilities was the main army base to support the US Army's efforts to control the Indians throughout the greater southwest.
American Indian Wars
The Dakota War of 1862 (more commonly called the Sioux Uprising of 1862 in older authorities and popular texts) was the first major armed engagement between the U.S. and the Sioux. After six weeks of fighting in Minnesota, led mostly by Chief Taoyateduta (aka, Little Crow), records conclusively show that more than 500 U.S. soldiers and settlers died in the conflict, though many more may have died in small raids or after being captured. The number of Sioux dead in the uprising is mostly undocumented, but after the war, 303 Sioux were convicted of murder and rape by U.S. military tribunals and sentenced to death. Most of the death sentences were commuted by President Lincoln, but on December 26, 1862, in Mankato, Minnesota, 38 Dakota Sioux men were hanged in what is still today the largest penal mass execution in U.S. history.