In its main features the Declaration of Independence is a great spiritual document. It is a declaration not of material but of spiritual conceptions.… - Calvin Coolidge

Other people have marveled at the growth and strength of America. They have wondered how a few weak and discordant colonies were able to win their independence from one of the greatest powers of the world. They have been amazed at our genius for self-government. They have been unable to comprehend how the shock of a great Civil War did not destroy our Union. They do not understand the economic progress of our people. It is true that we have had the advantage of great natural resources, but those have not been exclusively ours. Others have been equally fortunate in that direction. The progress of America has been due to the spirit of the people. It is in no small degree due to that spirit that we have been able to produce such great leaders. If coming generations are to maintain a like spirit, it will be because they continue to support the principles which these men represented. It is for that purpose that we erect memorials. We can not hold our admiration for the historic figures which we shall see here without growing stronger in our determination to perpetuate the institutions which their lives revealed and established.

Nothing in this world can take the place of persistence. Talent will not: nothing is more common than unsuccessful men with talent. Genius will not: unrewarded genius is almost a proverb. Education will not: the world is full of educated derelicts. Persistence and determination alone are omnipotent.

It has seemed to me that our search for this mysterious factor of difference must lead to the conclusion that it was not a single factor but the united workings of at least three forces, that brought about the wide difference.