Returning to the United States, in 1859 he was appointed assistant professor of chemistry at Columbia College, where he remained until 1860 when he was appointed professor of chemistry, botany, and physics at Antioch College. In 1861 he was married to Rebecca Stanley Wilmarth. Following the start of the American Civil War, he became chief clerk and hospital visitor for the United States Sanitary Commission during 1862–64, whereupon he was named professor of chemistry for the Pennsylvania State College. In 1867 he became vice president of the college.[2]
With the founding of Cornell University in 1868, he was recruited to serve as professor of agriculture and analytic chemistry—becoming the first professor appointed at the University.[2] While Dr. Caldwell was chair of the chemistry department at Cornell, it expanded from a single classroom and laboratory into a department that occupied two buildings, making it one of the world-leaders in chemistry education and research.[4] A number of graduates of the department, among whom were students of Dr. Caldwell, became notable soil scientists.[5] In 1869, he published Agricultural Chemical Analysis, the first textbook on agricultural science.[6] He became head of the newly founded Cornell University Agricultural Experiment Station in 1879. In 1903, Caldwell was named professor emeritus,[2] then he retired on June 7, 1906.[7] He died September 7, 1907, at Ithaca, New York.[4]
^ abcdeGreen, W. J. (1910), Bailey, L. H. (ed.), "Farm and community", Cyclopedia of American Agriculture, vol. 4 (2nd ed.), New York: The Macmillan Company, p. 560.
^Good, Gregory, ed. (1998), "Sciences of the Earth: A-G", Garland encyclopedias in the history of science, vol. 3, Psychology Press, p. 22, ISBN081530062X, retrieved 2013-04-28.
^ abWiley, Harvey W., ed. (1908), "Obituary", Bulletin, U.S. Department of Agriculture Bureau of Chemistry, no. 116, Washington, D.C.: U.S. Government Printing Office, p. 132.
^"George Chapman Caldwell", The Carnegie Foundation for the Advancement of Teaching, New York: U.S. Government Printing Office, p. 116, 1907.