I am thinking of going into pediatrics to treat infants, children, and adolescents.
That's awesome!  General pediatrics or specialty?
Pediatricians could do either, but I think I would like to be a primary care physician rather than specialize in something like neonatology.
What kind of schooling would that require?
Lots.  I would need to graduate from medical school, then have postgraduate training in pediatrics.
Do you know when the first pediatriac practice began?
, healer"). Pediatricians work both in hospitals, particularly those working in its subspecialties such as neonatology, and as outpatient primary care physicians.
History.
Already Hippocrates, Aristotle, Celsus, Soranus, and Galen understood the differences in growing and maturing organisms that necessitated different treatment: "" ("In general, boys should not be treated in the same way as men").
Some of the oldest traces of pediatrics can be discovered in Ancient India where children's doctors were called "kumara bhrtya
American Osteopathic Board of Pediatrics
The American Osteopathic Board of Pediatrics (AOBP) is an organization that provides board certification to qualified Doctors of Osteopathic Medicine (D.O.) who specialize in the diagnosis and treatment of medical diseases in infants, children, and adolescents (pediatricians). The board is one 18 medical specialty certifying boards of the American Osteopathic Association Bureau of Osteopathic Specialists approved by the American Osteopathic Association (AOA), and was established in 1940. As of December 2011, 477 osteopathic pediatricians held active certification with the AOBP