Transportation is one of the most basic responsibilities of governments in the United States. Public programs supported the initial construction of much of the nation's railroad system, the building of nearly all of the nation's roads and highways, the development of the air transportation system, and the construction of many of the facilities and routes used for water transportation. Government regulations have significantly affected all of the major transportation modes to one degree or another, and government funding has supported much of the research to develop new transportation technologies. No significant aspect of the transportation system has escaped the influence of public policies.
The U.S. transportation system has changed substantially since World War II. The construction of the Interstate Highway System greatly enhanced the appeal of road transportation, both for passengers and freight. Air travel became the dominant public carrier mode for intercity passenger travel. In addition, the national government found itself in the passenger train business.
Early in U.S. history, passenger travel was often difficult and uncomfortable. People walked or traveled by horse, generally on dirt roads. Travelers along the coast could go by boat, an option that was also available on some rivers and, later, on canals. With the coming of the railroads, people gained the ability to travel farther and faster than most had ever imagined. Although the early passenger trains were not very comfortable, track and equipment gradually improved. The railroads helped to link different sections of the country and speeded the settlement of the western United States.
The railroads were among the first big businesses in the United States, and major railroad executives became celebrities. By 1900, a traveler on a first-class train could expect to find good food, a library, a barber shop, and the company of prominent individuals from the worlds of business, politics, and entertainment. Passenger trains appeared in a wide range of