Dr. Henry C. Allen was born on February 2, 1836 in Ontario, Canada. Shortly after completing his medical studies, he joined the northern states army, where he served as a surgeon under General Grant.
After the war, he was offered and accepted the chair of anatomy at his alma mater in Cleveland, where he began to practice. He later resigned to take up an equivalent position at the Hahnemann Medical College, Chicago. In 1880 he became professor of materia medica at the University of Michigan.
In 1892, he founded the Hering Medical College and Hospital, where he was deacon and professor of materia medica until his death on January 22, 1909.