This book is a study of the capital transfers to the United States in the nineteenth and twentieth centuries and, for the latter decades of that period, of the transfers from the United States to the rest of the world - particularly Canada, the Caribbean, Mexico, and Central and South America. It provides a quantitative estimate of the level and industrial composition of those transfers, and qualitative descriptions of the sources and uses of those funds; and it attempts to assess the role of those foreign transfers in the economic development of the recipient economies. In the process, it describes the evolution of the American domestic capital market. Finally, it explores the issue of domestic political response to foreign investment, attempting to explain why the political reaction was so negative and so intense in Latin America and in the American West, but so positive in Canada and the eastern United States.