Quantrill's Raiders were the best-known of the pro-Confederate partisan guerrillas (also known as "bushwhackers") who fought in the American Civil War. Their leader was William Quantrill and they included Jesse James and his brother Frank.

Early in the war Missouri and Kansas were nominally under Union government control and became subject to widespread violence as groups of Confederate bushwhackers and anti-slavery Jayhawkers competed for control. The town of Lawrence, Kansas, a center of anti-slavery sentiment, had outlawed Quantrill's men and jailed some of their young women. In August 1863, Quantrill led an attack on the town, killing more than 180 civilians, supposedly in retaliation for the casualties caused when the women's jail collapsed.

The Confederate government, which had granted Quantrill a field commission under the Partisan Ranger Act, was outraged and withdrew support for such irregular forces. By 1864 Quantrill had lost control of the group, which split up into small bands. Some, including Quantrill, were killed in various engagements. Others lived on to hold reunions many years later, when the name Quantrill's Raiders began to be used. The James brothers formed their own gang and conducted robberies for years as a continuing insurgency in the region.

Lawrence is the county seat of Douglas County, United States, and sixth-largest city in Kansas. It is in the northeastern sector of the state, astride Interstate 70, between the Kansas and Wakarusa Rivers. As of the 2020 census, the population of the city was 94,934. Lawrence is a college town and the home to both the University of Kansas and Haskell Indian Nations University.

Lawrence was founded by the New England Emigrant Aid Company (NEEAC), and was named for Amos A. Lawrence, a Republican abolitionist originally from Massachusetts, who offered financial aid and support for the settlement. Lawrence was central to the "Bleeding Kansas" period (1854–1861), and the site of the Wakarusa War (1855) and the Sacking of Lawrence (1856). During the American Civil War it was also the site of the Lawrence massacre (1863).

Lawrence began as a center of free-state politics. Its economy diversified into many industries, including agriculture, manufacturing, and education, beginning with the founding of the University of Kansas in 1865 and Haskell Indian Nations University in 1884.