In the early 1860s, Irish immigrants in the United States were eager to help the Fenian brotherhood overthrow the British in Ireland. The American Fenians' mission: to invade British North America and hold it hostage. New Brunswick, with its large Irish population and undefended frontier, was a perfect target. The book tells how, in the spring of 1866, a thousand Fenians massed along the St. Croix River and spread terror among New Brunswickers. When the lieutenant-governor called in British soldiers and a squadron of warships, the Fenians saw that New Brunswick was no longer an easy target, and they turned their efforts against central Canada. The Fenian "attacks" and the demand for home defence fanned the already red-hot political debate, and a year later, in July 1867, New Brunswick joined Confederation. Turning Back the Fenians is volume eight in the New Brunswick Military Heritage Series.