Born in Winston-Salem, North Carolina on April 15, 1912, Jasper Brown Jeffries was an African American physicist and mathematician who worked on the Manhattan Project in World War II. The eldest child of Brown and Edna Jeffries, Jasper had three younger brothers, Carl, Hubert, and Robert.
Jeffries earned his B.S. degree in 1933 from West Virginia State College (WVSC), an Historically Black College and University (HBCU) located in Institute, West Virginia. While attending West Virginia State College, Jeffries enrolled in classes taught by Dr. Angie Turner King, also a 1927 graduate of the institution. King earned a masters degree in mathematics and chemistry in 1931 from Cornell University and later earned a doctoral degree in mathematics and chemistry in 1955 from the University of Pittsburgh. This is very significant because King represented the small numbers of African American women earning graduate degrees in the STEM (science, technology, engineering, mathematics) fields during this time period. It is highly plausible that King encouraged Jeffries to further his education and pursue a graduate degree. After earning his B.S. degree from West Virginia State College, Jeffries briefly attended the University of Illinois (1933-35). He later earned his M.S. degree in physical sciences from the University of Chicago in 1940.
After completing his M.S. degree, Jeffries worked as a physicist on the Manhattan Project (Metallurgical Laboratory) between 1943 and 1946 at the University of Chicago. Other African American scientists hired at the Chicago laboratory included Harold Delaney, Moddie Taylor, and Benjamin F. Scott. The Manhattan Project, one of the most important scientific projects of the 20th century, led to the development of the atomic bomb which ended World War II.
Jeffries held several academic and industrial positions after his appointment on the Manhattan Project. From 1946 to 1949, he served as a Professor and Chair in the Department of Physics at North Carolina Agricultural &Technical University in Greensboro, North Carolina, joining his colleague Delaney who was a faculty member in the Department of Chemistry at this time. For almost a decade, Jeffries worked as a Senior Engineer for the the Control Instrument Company (1951-59) located in New York. From 1963 to 1971, Jeffries worked as an Assistant Professor of Mathematics at Westchester Community College in Valhalla, N.Y. In 1971, Jeffries was promoted to Professor and became Chair of the department.
In 1937, Jeffries married Marguerite Diffay, a native of Birmingham, Alabama. Diffay earned a degree from Fisk University and a master of social work (M.S.W.) from the University of Chicago. The Jeffries had three daughters, Edna, Hazel, Marguerite, and a son, Jasper Brown, III.
Jasper Brown Jeffries died on July 16, 1994 in White Plains, New York. He was 82.