The following is from Wikipedia, which you can read there, but it seems so pertinent to the United States today that I am repeating some of it here.
Civic virtue is a concept that refers to the set of habits, values, and attitudes that promote the general welfare and the effective functioning of a society. Closely linked to the concept of citizenship, civic virtue (virtus) represents, therefore, the disposition of citizens to put the common good (bonum commune) before special interests. The identification of the character traits that constitute civic virtue has been a major concern of political philosophy. The term civility refers to behavior between persons and groups that conforms to a social mode (that is, in accordance with the civil society), as itself being a foundation of society and law.
In republics
Civic virtues are historically taught as a matter of chief concern in nations under republican forms of government, and societies with cities. When final decisions on public matters are made by a monarch, it is the monarch’s virtues which influence those decisions. When a broader class of people become the decision-makers, it is then their virtues which characterize the types of decisions made. This form of decision-making is considered superior in determining what best protects the interests of the majority. Aristocratic oligarchies may also develop traditions of public lists of virtues they believe appropriate in the governing class, but these virtues differ from the general civic virtues; for example, ruling class virtues stress martial courage over commercial honesty. Constitutions became important in defining the public virtue of republics and constitutional monarchies. The earliest forms of constitutional development can be seen in late medieval Germany (see Communalism before 1800) and in the Dutch and English revolts of the 16th and 17th centuries.
In ancient Greece and Rome
See also: Arete (moral virtue) and Virtus (virtue)
In the classical culture of Europe and those places that follow its political tradition, concern for civic virtue starts with the oldest republics of which we have extensive records, Athens and Rome. Attempting to define the virtues needed to successfully govern the Athenian polis was a matter of significant concern for Socrates and Plato; a difference in civic vision ultimately was one of the factors that led to the trial of Socrates and his conflict with the Athenian democracy. The Politics of Aristotle viewed citizenship as consisting, not of political rights, but rather of political duties. Citizens were expected to put their private lives and interests aside and serve the state in accordance with duties defined by law.
Rome, even more than Greece, produced a number of moralistic philosophers such as Cicero, and moralistic historians such as Tacitus, Sallust, Plutarch and Livy. Many of these figures were either personally involved in power struggles that took place in the late Roman Republic, or wrote elegies to liberty which was lost during their transition to the Roman Empire. They tended to blame this loss of liberty on the perceived lack of civic virtue in their contemporaries, contrasting them with idealistic examples of virtue drawn from Roman history, and even non-Roman “barbarians“.