After John Brown's death John Brown, Jr., had an officer's commission in a New York infantry regiment, but his fellow officers did not accept him. He late moved to Portland, Oregon and had a son, also named John Brown, who had a dental practice in Portland.
The fight between the Abolitionists and the Border Ruffians had the Abolitionists using what appeared to be either pattern 1853 Enfields, or 1861 Springfields. In reality the Abolitionists preferred Sharps rifles, smuggled through in crates labeled "Bibles". They therefore got the nickname Beacher' s Bibles, named after abolitionist Henry Ward Beacher.
The trivia item below may give away important plot points.
When Brown was hanged there was actually a huge crowd in attendance, not just the soldiers detailed for the duty. Stonewall Jackson, then in charge of a contingent of VMI cadets, was present, as was John Wilkes Boothe.