After Dr. Hamilton died in 1929, much of the groundwork for the new Society had to be laid by Dr. Allen who served as its first national president (1924–1931) and then national secretary (1931–1947). Pi Gamma Mu had for its succeeding presidents several distinguished social scientists, including the noted sociologist and American Sociological Association president Charles Abram Ellwood of Duke University, co-founder of the society and its president from 1931 to 1937, Dr. S. Howard Patterson (president, 1937–1951), a renowned microeconomist who was then professor of economics at the Wharton School of the University of Pennsylvania and author of several classic textbooks in the field, and political scientist W. Leon Godshall of Lehigh University, the society's president from 1951 until his untimely death in 1956 and under whose initiative the founding of foreign chapters was authorized.