Book excerpt: Mass immigration to the United States was nowhere more apparent than in the immigration of the Irish between 1815 and the failure of the potato crop in 1845/1846, during which time a million Irish men and women emigrated here. This book provides a detailed account of the economic, social, and political factors underlying the early migrations; an examination of the emigrant trade and its links with American shipping interests; and a history of government policy regarding assisted and unassisted emigration.