A review of the early sheriff-constable system notes that the expediency of patronage was the usual criterion for the selection of law enforcement personnel until well into this century. The only training available was that of experience. American insistence on local control of police is at least partly responsible for the absence of a national, repressive police force such as has arisen in other nations. Defects of the system are also observed, including the corruptibility of sheriffs and their unwillingness to enforce certain laws. The sheriff-constable system, however, was inadequate from the beginning in the crowded, often squalid cities spawned by industrialization. To meet the demands of growing lawlessness in urban areas, 'night watches' were formed to patrol the cities. Eventually, these watches developed into police departments. The beginnings of formal police training and education are discussed in reference to the work of August Vollmer, a marshall in Berkeley, Calif., the New York City Police Department's academy, and college programs initiated by Vollmer in various parts of California. In addition, the development of Federal and State police agencies is highlighted, including the FBI, the Traffic Institute of Northwestern University (Illinois), and the Southern Police Institute of the University of Louisville (Kentucky). A section on trends in academic involvement notes that the end of World War II marked the beginning of the explosion in police education. The recent availability of substantial Federal funds also has influenced the accelerated rate at which new programs in law enforcement are being initiated. Footnotes and about 25 references are provided.