The Harvard Guide has a long and distinguished history in the annals of reference works. First prepared in 1896 by Albert Bushnell Hart and Edward Charming, it was a unique scholarly tool. Revised in 1912 by Hart, Charming, and Frederick Jackson Turner, the Guide carried its entries through 1910 and became the standard text. In 1954 the Harvard Guide to American History appeared, prepared and edited by members of the History Department of Harvard: Oscar Handlin, Arthur Meier Schlesinger, Samuel Eliot Morison, Frederick Merk, Arthur Meier Schlesinger, Jr., and Paul Herman Buck. A one-volume compendium, the Guide became a classic in historical studies and won a place in every important library both public and private of American history. Now twenty years later, Frank Freidel, Charles Warren Professor of American History at Harvard, and Richard K. Showman, of the Rhode Island Historical Society, have made the Guide, once more, the most essential reference book for historians. Their work was sponsored by the Charles Warren Center for Studies in American History at Harvard. This thoroughly revised, comprehensive guide to American history reflects the explosive growth in historical publications and materials in the past two decades, and the expanding interests of American historians. About one third of the entries are new. These not only represent the surge of books and articles during the last generation, but also reflect new areas of history. The brief topical sections in the last edition have grown into a 300-page coverage of economic, social, and intellectual history. Demography, social structure, ethnicity, and the new urban and cultural dimensions of history find a place. Colonial history receives both topical and chronological treatment in an all-inclusive section. United States history since 1759, primarily political and diplomatic, appears in the familiar chronological form. Enlarged and up-to-date sections cover research methods and material. There are practical suggestions on research, writing, and publication, and extensive citation of finding aids and bibliographies to introduce the user to collections of printed materials, public documents, microform, manuscripts, and archives. The section on care and editing of manuscripts, long standard on the subject, appears unchanged; other sections, such as those on automated data retrieval, quantitative techniques, and oral history, reflect innovations in the historian s craft. The new Guide has been recast in columnar form to make it easier to locate references and includes crossreference by pages and sections to facilitate faster use.