Nonsense.
Brown's raid was a criminal -- indeed terrorist -- act for which he was captured by Federal troops, tried and hanged.
The Federal government could not have done more, or acted more correctly regarding Brown himself.
Brown's northern supporters are another matter.
If I remember correctly, they were not known at the time, and when they finally were exposed fled the US to avoid prosecution.
As for the propaganda value of Brown's raid, in helping convert reluctant Northern Democrats into ardent abolitionist Republicans -- well, there is that small matter of the US Constitution's First Amendment, guaranteeing freedom of the press.
So while the Slave Power did its utmost to suppress abolitionist literature in the South, there was no way they could prevent the Brown story from carrying a strong abolitionist message.
Bottom line: Brown's 1859 raid and hanging was no "war" against the South, but it was propagandized to help elect abolitionist Republicans in 1860.
And that's exactly the way the US Constitution intended such matters to be handled, FRiend.
In the end, as you well know: slavery had to be, and would have been, defeated one way or the other.
But the Slave Power in 1860 decided it would not (to quote Dylan Thomas) "go gentle into that good night..."
But would rather "Rage, rage against the dying of the light".
A rage that continues, now somewhat, ah, muted, to this very day... ;-)
Gosh you are good at this.
“Brown’s northern supporters are another matter.
If I remember correctly, they were not known at the time, and when they finally were exposed fled the US to avoid prosecution.”
That’s true. There were six of them and some did flee when newspapers began to link them to Brown. But exile was temporary except for one who died in Europe in 1860.
The ‘Secret Six’ were Thomas Wentworth Higginson, Samuel Gridley Howe, Theodore Parker, Franklin Benjamin Sanborn, Gerrit Smith, and George Luther Stearns. Unitarian ministers, authors, industrialists, social reformers, heirs to great fortune. They were wealthy and prominent men. The rich liberal elite of Massachusetts in the 19th Century.