In tracing the history of policing, the article notes that the establishment of laws and methods of enforcing them through policing mechanisms date back thousands of years. Attention is given to policing in Colonial America and after the Revolutionary War. A review of Federal statutory authority for the establishment of a police force advises that although the U.S. Constitution does not provide for the founding of a police force, the Tenth Amendment does, as it states that "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people." This gives States the power to enact laws and establish a police force. This power is then transferred to municipalities within the States. Although the State gives power to its municipalities to enact legislation to form a police force and define the authority and duties of officers, these powers cannot conflict with or exceed the power given to them by the State. Case law cited in this article suggests that much of the legal authority of the police is shaped by the courts as they interpret the laws. Four important innovations within the police system have helped define police authority as it currently exists: a command structure similar to that of the military; the restructuring of city governments to allow the police to come under the mayor's office rather than the courts; the institution of a city requirement that their police wear uniforms; and the inception of the police patrol. These innovations have defined the regimented organization of the police and increased police visibility among the citizenry. The article advises that the legal authority of the police is not static, but evolves over time and is constantly changing under new legislation and court interpretations of law. 46 references