The Fenian raids were a series of incursions carried out by the Fenian Brotherhood, an Irish republican organization based in the United States, on military fortifications, customs posts and other targets in Canada (then part of British North America) in 1866, and again from 1870 to 1871. A number of separate incursions by the Fenian Brotherhood into Canada were undertaken to bring pressure on the British government to withdraw from Ireland, although none of these raids achieved their aims.