In May, of 1863, Quantrill and his band moved closer to the Missouri-Kansas border. Brigadier General Thomas Ewing, Jr. from Kansas, who commanded the district border, was not happy with Quantrill’s presence. Soon, he issued General Order Number 10, which stated that any person - man, woman or child, who was directly involved with aiding a band of guerrillas would be jailed.

The idea was, by taking away the Border Ruffians means of food and shelter; the guerillas would leave the area. Before long, women and children were rounded up and placed in a dilapidated three story building in downtown Kansas City, Missouri. Of particular interest to the Federal Troops were the known relatives of the Border Ruffians, including family members of "Bloody Bill” Anderson and the Younger Brothers.

Though signs that the building housing the women and children was unstable, such as large cracks in the walls and ceilings, and large amounts of mortar dust on the floor, the signs were ignored. On August 13, 1863, the building collapsed killing 5 women and injuring dozens of others.

Among the killed and injured in the collapse were women who were close relatives of prominent Confederate guerrillas. Those killed in the collapse, included Josephine Anderson, sister of "Bloody Bill Anderson", Susan Crawford Vandever and Armenia Crawford Selvey, Cole Younger's cousins, Charity McCorkle Kerr, wife to Quantrillian member Nathan Kerr, and a woman named Mrs. Wilson. Many others were injured and scarred. Caroline Younger, sister to Cole and James Younger, would die two years later as a result of her injuries. Another Anderson sister was crippled for life, when both of her legs were broken in the incident.

When news of the collapse reached the families of the dead and injured, they went wild. Soon crowds began to gather around the ruins as the dead and wounded were carried off, shouting "Murder!" at the Union forces. Just four days later on August 18, 1863, General Ewing issued General Order Number 10, which "officially" stated that any person - man, woman or child, who was directly involved with aiding a band of guerrillas would be jailed.

Later, Quantrill and his men would claim that the building was deliberately weakened, giving them ammunition for the infamous attack on Lawrence that was about to come.

Early on the morning of August 21, 1863, Quantrill, along with his murderous force of about 400, descended on the still sleeping town of Lawrence, Kansas. Incensed by the free-state headquarters town, Quantrill set out on his revenge against the Jayhawker community.