Louis Agassiz (1807–1873), in addition to his work on paleoichthyology, had a substantial impact on geological thinking. He is the major figure in the development of Ice Age theory. One of his research areas was Maine. He was very influencial in higher education in Maine and New England, both in his ideas and through his students. This paper also discusses the work of researchers leading to Agassiz's development of a holistic view of an ice age.