In June 1866, an 800-man contingent of the Irish Fenian Brotherhood invaded Canada from Buffalo, New York, in an effort to free Ireland from British rule. The force was led by Irish-born John Charles O'Neill, a veteran of the Union Army's 5th Indiana Cavalry. The three-day invasion was a military success but a political failure, yet O'Neill was celebrated for his leadership and humanity. Elevated to the presidency of the Fenian...