This chapter discusses the development of administrative law in the in the second half of the nineteenth century covering the coming of bureaucrats, infrastructure regulation, occupational licensing, and the Sherman Antitrust Act. The administrative agency was the child of necessity. Government was growing, at all levels, and this created a need for specialists and specialized bodies. The period between 1850 and 1900 sometimes looks as if this was a kind of climax of laissez-faire—the age of Social Darwinism, the businessman’s earthly kingdom in the United States. Obviously, there is some truth to this idea. It was a period in which businessmen made loud noises, and won some great victories, at all levels of government. But some of this was defensive, a response to movement on the other side.