I saw this yesterday.

From President Calvin Coolidge’s “Address at the Celebration of the 150th Anniversary of the Declaration of Independence” in Philadelphia, July 5, 1926:

It was not because it was proposed to establish a new nation, but because it was proposed to establish a nation on new principles, that July 4, 1776, has come to be regarded as one of the greatest days in history. Great ideas do not burst upon the world unannounced. They are reached by a gradual development over a length of time usually proportionate to their importance. This is especially true of the principles laid down in the Declaration of Independence. Three very definite propositions were set out in its preamble regarding the nature of mankind and therefore of government. These were the doctrine that all men are created equal, that they are endowed with certain inalienable rights, and that therefore the source of the just powers of government must be derived from the consent of the governed.

If no one is to be accounted as born into a superior station, if there is to be no ruling class, and if all possess rights which can neither be bartered away nor taken from them by any earthly power, it follows as a matter of course that the practical authority of the Government has to rest on the consent of the governed. While these principles were not altogether new in political action, and were very far from new in political speculation, they had never been assembled before and declared in such a combination. But remarkable as this may be, it is not the chief distinction of the Declaration of Independence. . . . It was the fact that our Declaration of Independence containing these immortal truths was the political action of a duly authorized and constituted representative public body in its sovereign capacity, supported by the force of general opinion and by the armies of Washington already in the field, which makes it the most important civil document in the world.