Nothing in the struggle over slavery in Kansas did more to inflame the nation than the mass killing which took place May 19, 1858, about four miles northeast of this marker. Charles Hamelton who had been driven from the territory by Free-State men, retaliated by invading the county with about thirty Missourians. Capturing 11 Free-State men, he marched them to a ravine and lined them up before a firing squad. Five were killed, five were wounded, and one escaped by feigning death. The site and adjoining land, occupied for a time by John Brown, are preserved in a state memorial park. A monument bearing lines from Whittier's tribute to the victims stands in Trading Post cemetery south of here.
The town received its name from an Indian trading post established about 1834. A monument just east of the river marks the site. Here also, in January, 1859, John Brown dated his famous "Parallels."