Border ruffians carried the violence of Bleeding Kansas into Colorado.

Evidence

There, again, something was dropped out, but I suspect, and not without reason, that he joined one or more of those gangs of “border ruffians” which for so long raided through Kansas, perpetrating such massacres and outrages as that of the Marais du Cygne. — Isabella L. Bird, A Lady’s Life in the Rocky Mountains, 225

Categorization

• XREF: Connects to histories of Bleeding Kansas and the Marais du Cygne massacre as the training ground for later Western outlaws.