1928
Born in Evanston, Illinois to Jerome George Rozen and Della Kretchmar Rozen.
1946
Studies general studies and biology at the University of Pennsylvania.
1950
Receives a Bachelor of Arts and Science from the University of Kansas.
1955
Receives a Doctor of Philosophy from the University of California Berkeley.
1956
Becomes an entomologist in taxonomy of beetles for the U.S. Department of Agriculture.
1958
Becomes an assistant professor of entomology at Ohio State University.
1960
Becomes associate curator and chairman of the Department of Entomology at the American Museum of Natural History in New York, New York.
1961
Begins field expeditions in US, Europe, Mexico, Trinidad, Tobago, Argentina, Chile, Brazil, Peru, Venezuela, Morocco and Pakistan.
1961
Additional field expeditions include Republic of South Africa, Namibia, Israel, Egypt, Kyrgzstan, Turkey, Belize, Costa Rica and China.
1964
Becomes president of New York Entomology Society.
1965
Advanced to Curator with the Department of Entomology at the American Museum of Natural History in New York, New York.
1968
Becomes an adjunct professor at the City University of New York.
1972
Becomes deputy director for research at the American Museum of Natural History.
1990
Serves as president of the Organization of Biological Field Stations.
1999
Co-founds and organizes the Bee Course, an international workshop offered annually for 20 years.
2004
Becomes a museum associate at the University of Kansas Natural History Museum and Biodiversity Research Center.
2018
Retires and becomes curator and professor emeritus at the American Museum of Natural History.
2019
Ends field expeditions.