Price was initially neutral at the outbreak of the war and had come to see slavery in a negative light. Price had been a conditional Unionist but when Northern troops occupy military posts in Missouri he came to increasingly support the Confederacy. Price led Confederate troops for most of the war but his most famous involvement was the attempt to wage war against Union troops in Missouri in hopes of capturing control of the state and turning political opinion against the Union. From being a moderate supporter of the Union and hoping that Missouri could remain neutral or even help to bring the North and South together, Price became one of the most notorious Confederate raiders and led many deadly attacks on the people of his state.
In September of 1864, Price led an attack on pro-Union and neutral communities throughout Missouri, bringing destruction throughout the state in hopes of reversing his state's growing support of the Union. Price fled the United States and moved to Mexico after the war but returned two years later. He died on September 29, 1867 with a handful of supporters. Few Missourians would believe that he would be memorialized for his service to the Confederacy at the time of his death, but the UDC became increasingly influential throughout the state of Missouri by the early 20th century.