of his horses before returning to Missouri on the Santa Fe Trail. William and Jim Anderson soon formed a gang with a man named Bill Reed; in February 1863, the Lexington Weekly Union recorded that Reed was the leader of the gang. William Quantrill, a Confederate guerrilla leader, later claimed to have encountered Reed's company in July and rebuked them for robbing Confederate sympathizers; in their biography of Anderson, Albert Castel and Tom Goodrich speculate that this rebuke may have resulted in a deep resentment of Quantrill by Anderson. Anderson and his gang subsequently traveled east of Jackson County, Missouri, avoiding territory where Quantrill operated and continuing to support themselves by robbery. They also attacked Union soldiers, killing seven by early 1863. Quantrill's Raiders Missouri had a large Union presence throughout the Civil War, but was also inhabited by many civilians whose sympathies lay with the Confederacy. From July 1861 until the end of the war, the state suffered up to 25,000 deaths from guerrilla warfare, more than any other state. Confederate General Sterling Price failed to gain control of Missouri in his 1861 offensive and retreated into Arkansas, leaving only partisan rangers and local guerrillas known as "bushwhackers" to challenge Union dominance. Quantrill was at the time the most prominent guerrilla leader in the Kansas–Missouri area. In early 1863, William and Jim Anderson traveled to Jackson County, Missouri, to join him. William Anderson was initially given a chilly reception from other raiders, who perceived him to be brash and overconfident. In May 1863, Anderson joined members of Quantrill's Raiders on a foray near Council Grove, Kansas, in which they robbed a store west of the town. After the robbery, the group was intercepted by a United States Marshal accompanied by a large posse, about from the Kansas–Missouri border. In the resulting skirmish, several raiders were captured or killed and the rest of the guerrillas, including Anderson, split into small groups to return to Missouri. Castel and Goodrich speculated that this raid may have given Quantrill the idea of launching an attack deep in Kansas, as it demonstrated that the state's border was poorly defended and that guerrillas could travel deep into the state's interior before Union forces were alerted. In early summer 1863, Anderson was made a lieutenant, serving in a unit led by George M. Todd. In June and July, Anderson took part in several raids that killed