Question: The Immortal Ten were a group of free-staters that included a Kansas Territory Jayhawker who joined what during the American Civil War?
Sentence (from "Silas Soule"): Silas Stillman Soule (July 26, 1838 – April 23, 1865) was an American abolitionist, Kansas Territory Jayhawker, anti-slavery militant, and a friend of John Brown and Walt Whitman.
Relevant evidence: Yes