Hosmer Allen Johnson, M.D., L.L.D. (October 6, 1822 – February 26, 1891) was an American physician, academic, and Mason from New York. Badly injured on the family farm, Johnson turned to teaching to support himself. After graduating from the University of Michigan, he moved to Chicago, Illinois to attend Rush Medical College. There, he became an understudy of William B. Herrick and joined his medical practice. Receiving a Doctor of Medicine in 1852, Johnson was named Lecturer on Physiology at Rush, eventually chairing a department there. In 1859, he co-founded the Chicago Medical College at Lind University, which later became the Feinberg School of Medicine of Northwestern University. During the Civil War, Johnson was the top medical aide in the state, presiding over the Board of Medical E