Brigham Young declares war on Timpanogos in the Battle at Fort Utah.

Brigham Young was an American religious leader and politician. He was the second president of the Church of Jesus Christ of Latter-day Saints from 1847 until his death in 1877. He also served as the first governor of the Utah Territory from 1851 until his resignation in 1858.

The Timpanogos are a tribe of Native Americans who inhabited a large part of central Utah, in particular, the area from Utah Lake east to the Uinta Mountains and south into present-day Sanpete County.

The Provo River Massacre was a violent attack and massacre in 1850 in which 90 Mormon militiamen surrounded an encampment of Timpanogos families on the Provo River, and laid siege for two days. They eventually shot between 40 and 100 Native American men and one woman with guns and a cannon during the siege and subsequent pursuit, capture, and execution of the two groups that fled during the last night. One militiaman died and eighteen were wounded from return fire during the siege.