What happened at sand creek?

A massacre happened

Explanation:

The causes of the Sand Creek massacre were rooted in the long conflict for control of the Great Plains of eastern Colorado. The Fort Laramie Treaty of 1851 guaranteed ownership of the area north of the Arkansas River to the Nebraska border to the Cheyenne and Arapahoe. However, by the end of the decade, waves of Euro-American miners flooded across the region in search of gold in Colorado's Rocky Mountains, placing extreme pressure on the resources of the arid plains. By 1861, tensions between new settlers and Native Americans were rising. On February 8 of that year, a Cheyenne delegation, headed by Chief Black Kettle, along with some Arapahoe leaders, accepted a new settlement with the Federal government.