After graduation in 1923 Hacker started as assistant editor at the New International Encyclopedia, and was contributing editor at the New International YearBook. In 1935 he started as lifelong academic career at Columbia University as lecturer in economics.[3] In 1942 he became assistant professor, in 1944 Associate Professor, and in 1948 full Professor. After his retirement in 1967 he was appointed Professor Emeritus. In 1952 he was the first dean of its School of General Studies, where he served until 1958.[1]
In 1937 he had been visiting professor at the University Wisconsin,[3] in 1939 at the Ohio State University, in 1945 at Utah State Agricultural College, in 1953 at the University Hawaii, and in 1970 at the University Puget Sound. In 1948 he had been appointed Harold Vyvyan Harmsworth Professor of American History for one year at the University of Oxford. In addition to the scientific work, he was involved in the American Civil Liberties Union.
Hacker was a leading proponent of adult education. In an interview he had explained:
"Many students come to us 10, 20, 30 years after graduation from high school... They are intelligent and serious but they could not pass a college-entrance examination after such a long interruption of their studies. They want to try a college course, perhaps only one or two, before deciding whether they can go on. We let them try. Why not?"[4]
Hacker's research interests were in the field of American history and its social economic development, as well as the life and work of some of its greatest entrepreneurs such as Andrew Carnegie, Alexander Hamilton and Joseph M. Proskauer.
Louis M. Hacker & Benjamin Burks Kendrick. The United States since 1865. Appleton-Century-Crofts, New York, 1949 (prior editions in 1932, 1934, and 1939).
