Johnson was born on February 1, 1919, in Washington, District of Columbia, United States of America.
He accepted a post-doctoral fellowship in medical science with the Atomic Energy Commission at the University of Illinois, Chicago.
During that time, he was able to get a freeze drying apparatus (he had worked with inventor of the device, Isadore Gersh, while at the University of Illinois, Chicago) needed for research projects operational.
The ten day temporary duty became his career after General Elbert DeCoursey, AFIP Director, asked him if he wanted to stay.
[1][2] Johnson's most significant contribution included the histochemistry identification of a variety of substances in tissue sections.