Just as I thought - a few fringe characters attracted to a fringe loonie. Some of them referred to as a “Secret” group. There were never any throngs of admirers. There was never an official sanction by any government.
I will admit that there was an uptick in the curious who were attracted to all the fuss, but where were all of the “copy-cat” uprisings? The vast armies of grass-roots abolitionists sweeping over the southern countryside? It didn’t happen and those who squawked dire about it were looked upon as “chicken-little” characters.
John Brown was personally known to Frederick Douglass, who declined to get involved in Brown’s terrorism. Brown was well known among abolitionists.
The Secret Six were prominent men, rich men who supplied him with guns and pikes and wagons and whatever else he wanted. His past murders at Ossawatomie were known to them.
Brown was championed by the Transcendentalists, the premier literary set of the time. Brown’s supporters were far from fringe. They were rich and influential, similar to today’s Hollywood and Silicon Valley radicals.
‘To Purge This Land With Blood’, Stephen Oates, Univ of Massachusetts Press is a very detailed biography of John Brown.
Large sections of it are available for free at google books:
https://books.google.com/books/about/To_Purge_this_Land_with_Blood.html?id=ugB4_JPfieYC
Even a cursory reading will dispel the idea that Brown was a “fringe loonie” with insignificant admirers. He was very well known within abolitionist circles. He had known Frederick Douglass since 1847, and spent a month living with him in 1858 as he was hatching his conspiracy. His supporters, Gerrit Smith for example, owned mansions. They were men of means and influence.