The American branch of the Fenian movement -or the Irish Revolutionary Brotherhood- was founded in 1858. Its members were Irish nationalists forced into exile by political persecution or choosing exile to continue the struggle for independence after the collapse of the "Young Ireland" movement in 1848. Eventually the movement attracted many members in New York, New England, and the Great Lakes region, a development that caused much concern north of the border in British North America. The American Civil War provided new impetus for the Fenians. They felt that the ambiguous British position might draw the Union government into a war with Great Britain. Although this never materialized, the Fenians did use the Civil War as a training ground for its own soldiers. With about 150,000 to 175,000 Irish serving in the Union army, Northern politicians were becoming sympathetic to their cause. Thus the Fenians began planning their attack on British North America as the Civil War drew to a close. The Canadians, initially amused by the Fenian claims and demands, soon grew concerned that an invasion might result. And in 1866 the Fenians moved across the border to stage a series of raids. These raids, taking place at a time when Canadian politicians were urging Confederation, convinced many Canadians that such a move was desirable and advantageous. Fenianism in North America traces the Fenian movement and its impact on the emergence of Canadian national unity, probably the Fenians" most significant contribution. W.S. Neidhardt uses newspapers, diaries, and printed records of the period to bring this story to life. Cartoons of the era along with portraits of Fenian leaders and maps of the raids give the reader additional insight into the Fenian movement and its effects.