The Heritage Guide to the Constitution is intended to provide a brief and accurate explanation of each clause of the Constitution as envisioned by the Framers and as applied in contemporary law. Its particular aim is to provide lawmakers with a means to defend their role and to fulfill their responsibilities in our constitutional order.

The Constitution of the United States has endured for over two centuries. It remains the object of reverence for nearly all Americans and an object of admiration by peoples around the world. William Gladstone was right in 1878 when he described the U.S. Constitution as "the most wonderful work ever struck off at a given time by the brain and purpose of man."

The creation of the United States Constitution—John Adams described the Constitutional Convention as "the greatest single effort of national deliberation that the world has ever seen"—was a seminal event in the history of human liberty. The story of that creation in the summer of 1787 is itself a significant aspect in determining the meaning of the document.

Written constitutionalism implies that those who make, interpret, and enforce the law ought to be guided by the meaning of the United States Constitution—the supreme law of the land—as it was originally written. This view came to be seriously eroded over the course of the last century with the rise of the theory of the Constitution as a "living document" with no fixed meaning, subject to changing interpretations according to the spirit of the times.