The history of school psychology is developed with an analogy to human growth and development. "Conception" occurred, after several false starts, with the establishment of the psychological clinic at the University of Pennsylvania in 1896. "Gestation" extended until 1937 when certification for school psychologists was available in two states, and employment in the schools increased. "Infancy" lasted through the 1940s to the Thayer Conference in 1954. The increase in employment opportunities in the late 1950s and 1960s is comparable to the rapid growth of childhood. With accreditation by APA and the availability of diplomas from the American Board of Professional Psychology (ABPP), adolescence began. The significant persons in the field from 1895 to 1970 receive special attention.