Jennerjohn (b. 1922) was born in Milwaukee, Wisconsin.
He graduated from high school in 1940 and attended the Milwaukee School of Engineering for two years before transferring to the University of Wisconsin-Madison. In 1944, he was drafted into the Army; however, he was invited by General Groves to join the Manhattan Project in Los Alamos in 1945. Jennerjohn was a draftsman for the atomic bomb and painted the bomb that would eventually be dropped on Nagasaki. After the war, he continued to work for the nuclear program until 1946, when he returned to UW-Madison to get his Master's in Engineering. Afterwards, Jennerjohn joined the Wisconsin State Board of Health, Hospital Division and helped start many small hospitals in rural Wisconsin. He also worked to improve nursing homes, retiring from the Board of Health in 1984 at age 62.
From the description of Oral history interview with Dale J. Jennerjohn, [sound recording], 2006. (Wisconsin Veterans Museum Research Center). WorldCat record id: 526673650
