Nachdem er bis 1907 am Bryn Mawr College unterrichtete, war er zwischen 1907 und 1910 Professor an der Johns Hopkins University. Im Anschluss war er von 1910 bis zu seiner Emeritierung 1931 Professor für die Geschichte Amerikas an der Yale University.
Contemporary Europe, Asia, and Africa (= History of all Nations. Bd. 20). Williams & Norgate, London u. a. 1902.
A History of England. Allyn & Bacon, Boston MA u. a. 1903, Digitalisat.
Colonial Self-Government. 1652–1689 (= The American Nation. A History. Bd. 5). Harper & Brothers, New York NY u. a. 1904, Digitalisat.
British Committees, Commissions, and Councils of Trade and Plantations, 1622–1675 (= Johns Hopkins University Studies in Historical and Political Science. Series 26, Nr. 1/2/3, ISSN0075-3904). The Johns Hopkins Press, Baltimore MD 1908, Digitalisat.
The Colonial Period (= The Home University Library of Modern Knowledge. Nr. 47, ZDB-ID 986189-0). Henry Holt u. a., New York NY u. a. 1912, Digitalisat.
The Boston Merchants and the Non-Importation Movement. In: Colonial Society of Massachusetts. Transactions. Bd. 19, 1916/1917, ZDB-ID 349871-2, S. 160–259, (Auch Sonderabdruck. J. Wilson and Son, Cambridge MA 1917, Digitalisat).
Pilgrims and Puritans (= The Chronicles of America Series. Bd. 6, ZDB-ID 2382205-3). Yale University Press u. a., New Haven CT 1919;
The Fathers of New England. 1919;
Colonial Folkways. A Chronicle of American Life in the Reign of the Georges. 1919.
The Colonial Background of the American Revolution. 4 Essays in American Colonial History. Yale University Press u. a., New Haven CT 1924, (25th printing. Yale University Press, New Haven CT u. a. 1978, ISBN 0-300-00004-9).
The Colonial Period of American History. 4 Bände (Bd. 1–3: The Settlements. Bd. 4: England's Commercial and Colonial Policy.). Yale University Press u. a., New Haven CT 1934–1938, (Mehrere Nachdrucke).
The Rise and Fall of the New Haven Colony (= Tercentenary Commission of the State of Connecticut, Committee on Historical Publications. 48, ZDB-ID 2243098-2). Yale University Press, New Haven CT 1936.