What are the six purposes stated in the Preamble?

The six purposes stated in the Preamble of the Constitution are to form a more perfect union, establish justice, insure domestic tranquility, provide for the common defense, promote the general welfare, and secure the blessings of liberty to the present generation and to posterity. Each purpose responded to a real failure of the Articles of Confederation.

To form a more perfect union meant tightening the loose alliance of states into a workable national government, with shared currency, shared defense, and a common legal framework that could prevent the kind of interstate trade wars that had broken out in the 1780s. To establish justice committed the new government to creating federal courts capable of resolving disputes between citizens of different states, between states themselves, and between the United States and foreign citizens, in addition to upholding constitutional and statutory rights.

To insure domestic tranquility was a direct response to Shays' Rebellion in western Massachusetts in 1786 and 1787, where state government nearly collapsed under pressure from armed debtors. The federal government would have the power and duty to help suppress insurrections and keep public order.

To provide for the common defense addressed the obvious problem that thirteen independent state militias could not consistently protect against foreign powers like Britain, France, and Spain, all of which still had territorial interests in North America.

To promote the general welfare committed the federal government to acting for shared prosperity, including infrastructure, public credit, and economic stability. To secure the blessings of liberty for ourselves and our posterity tied the entire enterprise to the cause that had justified the Revolution and made clear that the new government was being constructed to safeguard freedom for future generations as well as the founding generation.

Together these six purposes form the constitutional mission statement. Subsequent articles distribute powers and structure institutions to carry the purposes into practice. When courts interpret ambiguous provisions, they often look back to the Preamble's purposes for guidance about the intent and ambition of the document. The Preamble does not grant power, but it announces the standards by which government should be judged.