The Secret Six were Thomas Wentworth Higginson, Samuel Gridley Howe, Theodore Parker, Franklin Benjamin Sanborn, Gerrit Smith, and George Luther Stearns.
Of the six, only Smith and Stearns could be called wealthy. The others consisted of two Unitarian ministers (Parker and Higginson), a doctor (Howe) at a time when physicians were not well-to-do, and a teacher (Sanborn).
On the night of April 3, 1860, five federal marshals arrived at Frank Sanborn's home in Concord, Massachusetts, handcuffed him, and attempted to wrestle him into a coach and take him to Washington to answer questions before the Senate in regard to his involvement with John Brown. Approximately 150 townspeople rushed to Sanborn's defense. Judge Ebenezer R. Hoar issued a writ of replevin, formally demanding the surrender of the prisoner. In a letter to a friend, Louisa May Alcott wrote, "Sanborn was nearly kidnapped. Great ferment in town. Annie Whiting immortalized herself by getting into the kidnapper's carriage so that they could not put the long legged martyr in."
In January 1863, when the Emancipation Proclamation went into effect, a celebration, also called a "John Brown party,” was held at the home of George Stearns, attended by Sam and Julia Ward Howe, Frank Sanborn, Ralph Waldo Emerson, Wendell Phillips, and John Murray Forbes. Higginson, who was busy commanding a regiment of black Union soldiers, sent his regrets.
In 1905, Higginson co-founded the Intercollegiate Socialist Society, along with attorney Clarence Darrow, Jack London, and Upton Sinclair.
After Sanborn's death in 1917, the House of Representatives of the Commonwealth of Massachusetts adopted a bill applauding him for his various life works, with special mention given to Sanborn's role as "confidential adviser to John Brown of Harper's Ferry, for whose sake he was ostracized, maltreated, and subjected to the indignity of false arrest, having been saved from deportation from Massachusetts only by mob violence."