Brown’s plan was to raid the federal armory at Harpers Ferry. He would use the weapons stolen to arm slaves so that they may revolt and free themselves.
The raid didn’t go well, Brown and his men were either killed or captured. Brown was tried and convicted of treason against the Commonwealth of Virginia, the murder of five men, and inciting a slave insurrection.
It’s righteous to take the right position when it’s not popular with the capitalists.
Learn more about John Brown on wikipedia.