Bleeding Kansas was a period of violence spurred on by President Pierce admitting Kansas into the US as a state with the requirement it would vote as to if slavery would be permissable there.
This led to advocates of both sides moving there in attempt to increase the chances of their side winning. Unfortunately adding numbers to the census wasn’t the only way to sway the election. There would be several attacks between partisans during this period, the one this sword featured in is known as the Pottawatomie massacre where it was used by John Brown the American Abolitionist of Harper Ferry fame. During that night 5 pro-slavery men would die.
In the words of abolitionist Frederick Douglass, it was “a terrible remedy for a terrible malady.”
Across the entirety of Bleeding Kansas 100+ (number disputed) anti-slavery advocates would die and fewer than 80 pro-slavery advocates would meet that same fate.
Ultimately Kansas was admitted as a free state in 1861, but sporadic violence would continue.
A good chunk of Brown’s stuff happened outside of Kansas. The jayhawkers and bushwhackers fought a ton. Both Lawrence and Manhattan in KS were burned to the ground by pro-slavery raiders. I’d assume the same stuff happened on the Missouri side but I’ve never read about that and that’s the same side that thought Mormons, who placed the garden of Eden near the KS border, were too crazy for thinking black people needed rights.