Benjamin Franklin appears on the $100 bill to commemorate the contributions he made to American history. As of 2014, the $100 bill is the highest-value note of American currency in circulation. Some of Franklin's contributions to history involve his political deeds with the fledgling United States and his role in bringing the French over to the American side in the Revolutionary War.
While many of the Founding Fathers played crucial roles in the birth of the United States, Franklin was one of the most significant. His assistance in writing the Declaration of Independence was vital in completing the draft and bringing all of the signatories into agreement.
The Revolutionary War would likely have had a different outcome if the French had not come to the aid of the former British colonies. Franklin played a major role in winning French aid, support that totaled tens of thousands of French francs toward the war effort against Great Britain. The French contributed troops and training to the colonists, and without those French funds, the colonies might have remained under British control far longer.
Franklin's many innovations and inventions also make him an important figure in American history. Whether it was the Franklin stove or bifocal glasses, his creativity and scientific aplomb made him a major figure in developing American industry.