the Civil War started, Connor volunteered for service in the Union army
and was appointed Colonel of the Third California Infantry with instructions
to guard and secure the overland mail route across the West. In October
1862 he moved his command to Salt Lake City, where he founded Camp Douglas and at once engaged in an acrimonious and bitter cold war with Brigham
Young and the Mormon people, whom he accused of being disloyal and immoral.
Connor won a brigadier general's star for his destruction of 250 northwestern Shoshoni at Bear River near Franklin, Idaho, on 29 January 1863. In
the spring of 1865, he was named commander of the District of the Plains
and placed in charge of the Powder River Expedition, whose goal was
to pursue and punish the Sioux, Arapaho, and Cheyenne Indians in what
is today Wyoming. The expedition was unsuccessful except for a band
of Arapaho Connor defeated at Tongue River on 29 August 1865. Connor
then returned to the military District of Utah where he was discharged
as a Brevet Major-General in the spring of 1866.