Megginson stayed on the LSU faculty, rising to Full Professor in 1960, before being named Professor Emeritus upon his retirement in 1977. While at LSU, Leon published some 100 articles and won numerous awards for teaching and research.
Leon served as President, Southwestern Social Science Association (1962); President, Southern Management Association (1973-1974); Founding President, North American Case Research Association (1980); and Chair, Management History Division of the Academy of Management (1983). A member of several honor societies, including Phi Kappa Phi, Beta Gamma Sigma, and Pi Gamma Mu, Leon was a Fellow of the Academy of Management (1973), the North American Case Research Association (1990), and the Southern Management Association (1995).