This book is the result of a commission from the American Pediatric Society in 1997 to develop a history of the pediatric specialties. Finberg and Stiehm convened a “committee to select the topics, choose the authors, solicit and edit the manuscripts.”
Most attention is devoted to those subspecialties in which one now becomes certified by pursuing a fellowship (usually 3 years following one's 3-year pediatric residency) before submitting to a certifying examination produced by the various subboards of the American Board of Pediatrics (ABP). That list (and the dates of their first examinations) includes cardiology (1961), hematology-oncology (1974), nephrology (1974), neonatology (1975), endocrinology (1978), pulmonology (1986), critical care (1987), gastroenterology (1990), rheumatology (1992), and adolescent medicine (1994).
Nelson NM. The American Pediatric Society History of Pediatric Subspecialties. Arch Pediatr Adolesc Med. 2007;161(5):525-526. doi:10.1001/archpedi.161.5.525