1892 – Allen was Canyon City, Colorado on May 2, 1892.
1915 – Received his bachelor’s degree from Brown University.
1916 – Received his master’s degree in biology from Brown University.
1918 – Married Marion Pfeiffer.
1919 – Appointed instructor and associate of anatomy at the School of Medicine of Washington University.
1921 – Received his Ph.D with a dissertation on biology from Brown University.
1923 – Became the chairman of anatomy at the school of medicine, University of Missouri.
1933 – Became professor of anatomy and chairman of the department at the Yale School of Medicine.
1937 – Became a member of the French Legion of Honour for hissignificant role in the advancement of modern endocrinology.
1939 – Elected president of the American Association of Anatomists and the Association for the Study of Internal Secretions. Served as an advisory trustee of the Scientific Advisory Committee of the International Cancer Research Foundation.
1943 – Died in New Haven, Connecticut on February 3, 1943.