ON OCTOBER 17, 1909, a small group of former abolitionists quietly gathered in an imposing brick house in Concord, Massachusetts, to commemorate the 50th anniversary of John Brown’s historic raid on the federal arsenal at Harpers Ferry, then a part of Virginia. Thomas Wentworth Higginson, Franklin B. Sanborn, and Julia Ward Howe, widow of Dr. Samuel Gridley Howe, did not want their meeting to attract attention, despite the fact that Brown and his compatriots were being celebrated across the country. The two old men, along with Samuel Howe and three other long-dead comrades, had once formed an abolitionist cabal known as the Secret Six who supplied Brown and his men with money and weapons as he prepared for the assault. Those six ardent abolitionists had, in effect, been planning treason against the United States.

Katherine Mayo, the young reporter who brought them together, was seeking momentous revelations. “Why do you want to know of us?” Higginson had written to Mayo. “Did any historian ever bother to write down the name of the man who bought the donkey on which Christ rode into Jerusalem? We of the Six were as unimportant and incidental to the real story of John Brown as that ancient Judean is to the story of our Lord. . . . We do not deserve remembering. Although there was no Judas among us, there were six Peters, all who denied John Brown at least once through some word or act before the cock crowed.”

Higginson’s self-effacement, while perhaps genuine, was incorrect. The story of these six avid enemies of slavery - writers, preachers, and businessmen - is not just an obscure tale about the would-be financiers of a revolution; it is also the story of pacifists-turned-radicals, of hope for slavery’s extinction being shattered by deep societal and economic currents, and of inspired citizens planning a stand against fundamental evil, only to flee the country and deny their involvement after Brown’s failure.

The Secret Six were not hardscrabble ruffians or ex-slaves, but men of culture, education, and fortune, and, as such, an especial threat to the slave-holding plutocracy. Five of the six were from Boston: Higginson was a preacher and a writer; Sanborn was a young writer, teacher, and protégé of Ralph Waldo Emerson; Howe was a world-renowned physician who worked with the blind and deaf; Theodore Parker was a well-known abolitionist and Unitarian preacher; and George L. Stearns was a prosperous manufacturer. The sixth member, Gerrit Smith, was a rich upstate New York businessman and philanthropist.

These men had known Brown for years through their abolitionist and Underground Railroad connections. Brown, in fact, at one time lived in Timbucto, a free black enclave created by Smith in the Adirondacks. Except for Higginson, the six men had generally followed a nonviolent ideology and vented their outrage in words. But unfolding events would challenge their assumptions.

The new Fugitive Slave Act--part of the Compromise of 1850 legislation required U.S. citizens to assist in the recovery of fugitives to whom it denied jury trial, and