John Y. Beall was a Confederate navy officer hanged as a spy by Union authorities at the end of the American Civil War (1861–1865). A militiaman who witnessed the execution of John Brown in 1859, Beall joined the Stonewall Brigade, fought with Turner Ashby, and participated in the Shenandoah Valley Campaign (1862), during which he became separated from his unit. He moved to Iowa and then to Canada, where he eventually joined the Confederate navy and planned and sometimes executed various clandestine missions. After capturing a Union merchant ship, Beall himself was captured and imprisoned briefly before being exchanged. He refused a commission in the Confederate secret service, but returned to Canada where he continued his clandestine work. After being captured again at Niagara Falls, this time when he attempted to derail trains carrying Confederate prisoners, Beall was tried for spying. The charges cited a failed attempt to seize a civilian passenger boat and use it to capture a Union gunboat, an aborted mission in which Beall disguised himself as a passenger. Beall was defended by a prominent New York City attorney and ninety-two members of the U.S. Congress signed a petition for his pardon, but he was hanged on February 24, 1865.