Born in Evanston, Illinois to Jerome George Rozen and Della Kretchmar Rozen.
Studies general studies and biology at the University of Pennsylvania.
Receives a Bachelor of Arts and Science from the University of Kansas.
Receives a Doctor of Philosophy from the University of California Berkeley.
Becomes an entomologist in taxonomy of beetles for the U.S. Department of Agriculture.
Becomes an assistant professor of entomology at Ohio State University.
Becomes associate curator and chairman of the Department of Entomology at the American Museum of Natural History in New York, New York.
Begins field expeditions in US, Europe, Mexico, Trinidad, Tobago, Argentina, Chile, Brazil, Peru, Venezuela, Morocco and Pakistan.
Additional field expeditions include Republic of South Africa, Namibia, Israel, Egypt, Kyrgzstan, Turkey, Belize, Costa Rica and China.
Becomes president of New York Entomology Society.
Advanced to Curator with the Department of Entomology at the American Museum of Natural History in New York, New York.
Becomes an adjunct professor at the City University of New York.
Becomes deputy director for research at the American Museum of Natural History.
Serves as president of the Organization of Biological Field Stations.
Co-founds and organizes the Bee Course, an international workshop offered annually for 20 years.
Becomes a museum associate at the University of Kansas Natural History Museum and Biodiversity Research Center.
Retires and becomes curator and professor emeritus at the American Museum of Natural History.
Ends field expeditions.