Source material for this article comes from an excellent US Department of State publication, The Great Seal of the United States:  Publication No. 10411.  It is for sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402.  It's also available for free download in Adobe PDF format: http://www.state.gov/www/publications/great_seal.pdf  Some wording and phrases from the original sources have been slightly edited / modified for middle school use by Sam Greene. 

Prior to reading this passage, make sure you've previewed the questions on the prior page to focus your reading of this article.  Previewing questions is a reading strategy you can and should use in all your classes.

For the past 6,000 years, cultures old and new have used seals, often instead of a signature, to formalize contracts and agreements. Like empires of old, the new United States needed an official emblem that could be used to authenticate signatures on her treaties and other official documents.

Before it adjourned on July 4, 1776, the Continental Congress of the newly independent United States passed a resolution: Resolved, that Dr. Franklin, Mr. J. Adams and Mr. Jefferson, be a committee, to bring in a device for a seal for the United States of America. Thus, three of the five men who had drafted the Declaration of Independence were brought together in further service to their country. The revolutionaries needed an emblem and national coat of arms to give visible evidence of a sovereign nation and a free people with high aspirations and grand hopes for the future. The task proved far more difficult than anticipated; it took six years, two more committees, and the combined efforts of 14 men before the Great Seal of the United States became a reality on June 20, 1782.

If you're wondering what the Great Seal is, it's the actual engraved metal die that impresses the design of the seal onto a document. It is also the impression made by the die (and the substance bearing the impression). Symbolically, the seal reflects the beliefs and values that the Founding Fathers attached to the new nation and wished to pass on to their descendants.  Most Americans don't know it, but they often carry around a piece of American history and heritage with them on a daily basis in their wallets or purses.  Our one dollar bill has both sides of the Great Seal on its back 

The Great Seal  is actually made up of two separate parts.  The Obverse Side of the Great Seal is the one that has the prominent American bald eagle supporting the shield, or escutcheon, which is composed of 13 red and white stripes, representing the original States, and a blue top which unites the shield and represents Congress. The Latin motto E Pluribus Unum means, "Out of many, one."  The olive branch and 13 arrows denote the power of peace and war, which is exclusively vested in Congress. The constellation of stars denotes a new State taking its place and rank among other sovereign powers.

The lesser known Reverse Side of the Great Seal is the one with the pyramid and the eye.  The pyramid signifies strength and duration:  The eye over it and the Latin motto Annuit Coeptis means, "He [God] has favored our under-takings." It suggests the many interventions of Providence in favor of the American cause. The date underneath, in Roman numerals, is that of the Declaration of Independence.  The words under it, Novus Ordo Seclorum, which translate as "A new order of the ages," signify the beginning of the new American era in 1776.

The Secretary of State is the person in charge of the actual Great Seal.  It is most often used on documents that serve a purpose in international affairs.  After they have been signed by the President of the United States, the following types of documents qualify for the Great Seal:

For obvious and less obvious reasons, the number 13 was symbolically very important to the Founding Fathers as they began designing the seal.  The most obvious reason, of course, was that there were 13 Colonies that came together to form the country.  There's been lots of debate and speculation on other reasons why the number 13 figures so prominently as a symbol in the Great Seal, but no one seems to know for sure.  As mentioned above, there are 13 arrows in the eagle's talon and 13 red and white stripes in the seal, but there are other examples of 13 present on the seal.  How many instances of 13 can you find in the Great Seal?  If the pictures below are too small, find a dollar bill; if you don't have one, I'll sell you one for two dollars.

THE GREAT SEAL OF THE UNITED STATES
(Observe on the left; Reverse on the right)