He was born in Providence, R.I., Apr. 4, 1866. In the 1890's Baker taught pioneering courses in public speaking and dramatic history at Harvard University; after 1904, his course, "English 47, The Technique of the Drama," became a major influence in the development of 20th century American drama. Between 1913 and 1924, "The 47 Workshop," a graduate laboratory course in the arts and techniques of the theater, produced important experimental plays. In 1925 Baker went to Yale University to found the Yale Drama School and to build the "University Theater," both of which he directed until his retirement in 1933. An accurate knowledge of theater history prompted his early use of radical concepts of lighting, of revolving and sliding stages, and of the newest modes of scenic and costume design.