Ron Guth: 1776 was a momentous year for the thirteen American Colonies. On July 4 of that year, delegates to the Continental Congress signed a Declaration of Independence, sending notice to England and the rest of the world that the Colonies would submit no longer to outside governance and interference. In recognition of the solidarity of the Colonies and their assumption of the right as a sovereign entity to coin their own monies, plans were made to issue a Silver Dollar. Patterns, using designs provided by Benjamin Franklin, were struck in Pewter, Brass, and Silver.
The denticles below the date on some of the "CURRENCY" varieties (and perhaps others) show a curious "shearing" effect where they are only partially attached to the coin (for example, see Superior Galleries 5/2001:1009). Sometimes the loose segments will actually shift out of position, creating the impression that a drunken engraver created the die.
Varieties (not all varieties are listed here):