Ka cika wannan magana: A shekara ta 1865, Roberts shi ne shugaban Fenian Society, wata ƙungiyar 'yan kishin ƙasa ta Irish da aka san ta da farmakin da take kai wa sansanonin Britaniya a Kanada. Ya shiga cikin
kai hari kan Kanada a 1866, wanda Gwamnatin ta kama shi.