This multiplicity of governmental units is best understood in terms of the evolution of the United States. The federal system, it has been seen, was the last step in an evolutionary process. Prior to the Constitution, there were the governments of the separate colonies (later states) and prior to those, the governments of counties and smaller units. One of the first tasks accomplished by the early English settlers was the creation of governmental units for the tiny settlements they established along the Atlantic coast. Even before the Pilgrims disembarked from their ship in 1620, they formulated the Mayflower Compact, the first written American constitution. And as the new nation pushed westward, each frontier outpost created its own government to manage its affairs.

The drafters of the U.S. Constitution left this multilayered governmental system untouched. While they made the national structure supreme, they wisely recognized the need for a series of governments more directly in contact with the people and more keenly attuned to their needs. Thus, certain functions -- such as defense, currency regulation and foreign relations -- could only be managed by a strong centralized government. But others - - such as sanitation, education and local transportation -- belong mainly to local jurisdictions.

Before their independence, colonies were governed separately by the British Crown. In the early years of the republic, prior to the adoption of the Constitution, each state was virtually an autonomous unit. The delegates to the Constitutional Convention sought a stronger, more viable federal union, but they were also intent on safeguarding the rights of the states.

In general, matters that lie entirely within state borders are the exclusive concern of state governments. These include internal communications; regulations relating to property, industry, business and public utilities; the state criminal code; and working conditions within the state. Within this context, the federal government requires that state governments must be democratic in form and that they adopt no laws which contradict or violate the federal Constitution or the laws and treaties of the United States.

There are, of course, many areas of overlap between state and federal jurisdictions. Particularly in recent years, the federal government has assumed ever broadening responsibility in such matters as health, education, welfare, transportation, and housing and urban development. But where the federal government exercises such responsibility in the states, programs are usually adopted on the basis of cooperation between the two levels of government, rather than as an imposition from above.

Like the national government, state governments have three branches: legislative, executive and judicial; and these are roughly equivalent in function and scope to their national counterparts. The chief executive of a state is the governor, elected by popular vote, typically for a four-year term (although in a few states the term is two years). Except for Nebraska, which has a single legislative body, all states have a bicameral legislature, with the upper house usually called the Senate and the lower house the House of Representatives, House of Delegates or the General Assembly. In most states, senators serve four-year terms and members of the lower house serve too-year terms.

The constitutions of the various states differ in some details but generally follow a pattern similar to that of the federal Constitution, including a statement of the rights of the people and a plan for organizing the government. On such matters as conditions governing the operation of businesses, banks, public utilities and charitable institutions, state constitutions are often more detailed and explicit than the federal one. Each state constitution, however, provides that the final authority belongs to the people, and sets certain standards and principles as the foundation of government.

Once predominantly rural, the United States is today a highly urbanized country, and more than three-quarters of its citizens now live in towns, large cities or the suburbs. This statistic makes city governments critically important in the overall pattern of American government. To a greater extent than on the federal or state level, the city directly serves the needs of the people, providing everything from police and fire protection to sanitary codes, health regulations, education, public transportation and housing.

The business of running America's major cities is enormously complex. Only seven states of the union, for example, have populations larger than that of New York City. It is often said that, next to the presidency, the most difficult executive position in the country is that of mayor of New York.

City governments are chartered by states, and their charters detail the objectives and powers of the municipal government. But in many respects the cities function independently of the states. For most big cities, however, cooperation with both state and federal organizations is essential to meeting the needs of their residents.

City Government Organization

Types of city governments vary widely across the nation. However, almost all have some kind of central council, elected by the voters, and an executive officer, assisted by various department heads, to manage the city's affairs.

There are three general types of city government: the mayor-council, the commission and the city manager. These are the pure forms; many cities have developed a combination of two or three of them.

Mayor-Council: This is the oldest form of city government in the United States and, until the beginning of this century, was used by nearly all American cities. Its structure is similar to that of the state and national governments, with an elected mayor as chief of the executive branch, and an elected council representing the various neighborhoods forming the legislative branch. The mayor appoints heads of city departments and other officials, sometimes with the approval of the council. He has the power of veto over city ordinances and frequently is responsible for preparing the city's budget. The council passes ordinances, the laws of the city, sets the tax rate on property and apportions money among the various city departments.

The Commission: This combines both the legislative and executive functions in one group of officials, usually three or more in number, elected city-wide. Each commissioner supervises the work of one or more city departments. One is named chairman of the body and is often called the mayor, although his power is equivalent to that of his fellow commissioners.

City Manager: The city manager is a response to the increasing complexity of urban problems, which require management expertise not often possessed by elected public officials. The answer has been to entrust most of the executive powers, including law enforcement and provision of services, to a highly trained and experienced professional city manager.

The city manager plan has been adopted by a growing number of cities. Under this plan, a small, elected council makes the city ordinances and sets policy, but hires a paid administrator, also called a city manager, to carry out its decisions. The manager draws up the city budget and supervises most of the departments. Usually, there is no set term; the manager serves as long as the council is satisfied with his or her work.

The county is a subdivision of the state, usually -- but not always -- containing two or more townships and several villages. New York City is so large that it is divided into five separate boroughs, each a county in its own right: The Bronx, Manhattan, Brooklyn, Queens and Staten Island. On the other hand, Arlington County, Virginia, just across the Potomac River from Washington, D.C., is both an urbanized and suburban area, governed by a unitary county administration.

In most counties, one town or city is designated as the county seat where the government offices are located and where the board of commissioners or supervisors meets. In small counties, boards are chosen by the county as a whole; in the larger ones, supervisors represent separate districts or townships. The board levies taxes, borrows and appropriates money, fixes the salaries of county employees, supervises elections, builds and maintains highways and bridges, and administers national, state and county welfare programs.

Thousands of municipal jurisdictions are too small to qualify as city governments. These are chartered as towns and villages and deal with such strictly local needs as paving and lighting the streets; ensuring a water supply; providing police and fire protection; establishing local health regulations; arranging for garbage, sewage and other waste disposal; collecting local taxes to support governmental operations; and, in cooperation with the state and county, directly administering the local school system.

The government is usually entrusted to an elected board or council, which may be known by a variety of names: town or village council, board of selectmen, board of supervisors, board of commissioners. The board may have a chairman or president who functions as chief executive officer, or there may be an elected mayor. Governmental employees may include a clerk, treasurer, police and fire officers, and health and welfare officers.

One unique aspect of local government, found mostly in the New England region of the United States, is the "town meeting." Once a year -- sometimes more often if needed -- the registered voters of the town meet in open session to elect officers, debate local issues and pass laws for operating the government. As a body, they decide on road construction and repair, construction of public buildings and facilities, tax rates and the town budget. The town meeting, which has existed for more than two centuries, is often cited as the purest form of direct democracy, in which the governmental power is not delegated, but is exercised directly and regularly by all the people.

The federal, state and local governments covered here by no means include the whole spectrum of American governmental units. The U.S. Bureau of the Census (part of the Commerce Department) has identified no less than 78,218 local governmental units in the United States, including counties, municipalities, townships, school districts and special districts.

Americans have come to rely on their governments to perform a wide variety of tasks which, in the early days of the republic, people did for themselves. In colonial days, there were few policemen or firemen, even in the large cities; governments provided neither street lights nor street cleaners. To a large extent, a man protected his own property and saw to his family's needs.

Now, meeting these needs is seen as the responsibility of the whole community, acting through government. Even in small towns, the police, fire, welfare and health department functions are exercised by governments. Hence, the bewildering array of jurisdictions.