James Lane, a Jayhawker Chieftain, led a band of Kansans in an attack on the town. Over two days, most of the town’s structures were burned, and in the public square nine citizens were executed.
On September 22, 1861, Osceola’s population was between 2,000 and 2,500. Two days later, it was down to 183.
Fury over the event—over time—led to Quantrill’s raid on Lawrence, Kansas on August 21, 1863. “Remember Osceola!” was shouted by William Clark Quantrill’s Confederate guerrillas during the attack.
After the event, Missouri farm boys and civilians joined the Missouri Partisan Rangers in order to defend themselves from the “tyrannical, murderous and criminal treatment” of innocent citizens.
The sacking of Osceola was the inspiration for the 1976 film “The Outlaw Josey Wales”, directed by and starring Clint Eastwood.
For more info: http://www.rulen.com/partisan/osceola.htm