Question: When did American abolitionist, Kansas Territory Jayhawker, anti-slavery militant, and a friend of John Brown and Walt Whitman, member of The Immortal Ten, die?
Sentence (from "John Brown's raid on Harpers Ferry"): John Brown had originally asked Harriet Tubman and Frederick Douglass, both of whom he had met in his transformative years as an abolitionist in Springfield, Massachusetts, to join him in his raid, but Tubman was prevented by illness, and Douglass declined, as he believed Brown's plan would fail.
Relevant evidence: No