Notes:
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.  

Images courtesy of Heritage Numismatic Auctions

Varieties (not all varieties are listed here):
Newman 1-C 
Newman 2-C 
Newman 3-D 

Significant examples:
In the February 2005 issue of NUMISMATIST (page 63), William Anton offered a 1776 Brass Continental Dollar for $375,000.00, describing it as follows: "Breathtaking Gem Uncirculated.  Finest known."

PCGS MS-65 (illustrated above).  Ex - Heritage Numismatic Auctions, Inc.'s "Long Beach Signature Sale", September 23-24, 1999, Lot 5389, "Pewter...Newman 3-D"

Recent appearances:
PCGS MS-64 (illustrated below).  Ex - Superior Galleries' "Pre-Long Beach Coin Sale", May 27-29, 2001, Lot 1008, plated, where it was described as follows: "1776 Continental Dollar in Pewter Breen-1095 PCGS graded Mint State-64. CURRENCY. Frosty bright light silvery gray. Absolutely choice except for a speck of tin pest on the base of the sundial, another on the ring under F in FUGIO, one on the face of the sun, and one on the line over R in YOUR. All of these are tiny and very shallow and do not detract for the outstanding eye appeal of this popular pattern for our earliest coinage. Usual die state with a crack meandering through most of the links on the reverse. The reverse is rotated 140 degrees CCW from normal coin orientation (head-to-foot)

PCGS MS-61 (illustrated below).  Ex - Paul Arthur Norris - Ira & Larry Goldberg Coins & Collectibles, Inc.'s "Pre-Long Beach Sale", September 23 & 24, 2002, Lot 49, illustrated, where it was described as follows: "Newman 2-C.  PCGS graded MS-61 Currency, Pewter. Light steel gray in color with the obverse very clean for the grade, on the reverse the color is also well matched, and we note a couple of trivial marks on some of the chain links. As expected, the strike is sharp throughout, with no weakness whatsoever. There are scattered lumps of tin pesting on both sides, but primarily on the reverse, as often seen on coins of this metallic content. For more than the last century, these were thought to have been struck in pewter, but they are actually tin, although similar, not quite the same alloys. Keeping with this numismatic tradition, PCGS notes on their insert "Pewter". PCGS has graded only one as such, with a dozen graded higher. Most are found in circulated grades.
The American Continental Congress anticipated a loan of silver for coinage from their friends in France, and hence unknown intermediaries contacted New Jersey engraver Elisha Gallaudet to make dies, employing his popular renderings of the sundial and chain with each state engraved one to a link. Coinage began in secret, pending the hoped for loan of silver from France, these were struck primarily in tin, a few in brass, copper and even a silver example or two are known. As a new nation, the United States needed to exercise its sovereign right to coin money, and further it was hoped that these coins would help prop up the rapidly deflating Continental Currency then in circulation. In theory, the Continental notes would then be redeemable in silver coin, supporting the notes stated value.
Many tin coins circulated, and their popularity remains high with the date 1776 emblazoned on the obverse, and the strong chain of the 13 original colonies linked on the reverse, with the bold statement WE ARE ONE at the center. The design elements had been sketched by Benjamin Franklin, and were seen on a few Continental currency notes attributed to Elisha Gallaudet by Eric Newman (see the Continental Currency chapter, issue of February 17, 1776 Resolution fractional notes). These notes were clearly copied for the coin herein, and misspellings of "currencey" are seen on both the notes as well as a few of the coins!
The true denomination is not known, although they are approximately the size of later dollars, and hence that name has stuck. Perhaps they were meant to be Pence, or something closer to a cent in circulating value when struck in tin. Highly popular with collectors, the design elements employ the medieval symbols of the Sun with Face (God or Time personified), while the sundial with FUGIO refers to Time or the Sun which is fleeing, so one must use Time or daylight hours, wisely. The motto, MIND YOUR BUSINESS means just that. On the reverse, each state is noted or abbreviated on a chain link, thirteen of which encircle the reverse, with the center circle surrounded by glory rays with AMERICAN CONGRESS surrounding WE ARE ONE at the very center. The original dies were modified from beaded links (2 examples known in brass), and this variety is thought to have been the first large group struck, and most show evidence of circulation. Apparently struck using medal turn (flip side to side, not top to bottom), the reverse had rotated about 40 degrees clockwise when this one was struck." - unsold - Ira & Larry Goldberg Coins & Collectibles, Inc. "The Benson Collection, Part III", February 24-25, 2003, Lot 15, illustrated, sold for $24,150.00

PCGS AU-58.  Ex - Superior Galleries' "Pre-Long Beach Coin Sale", May 27-29, 2001, Lot 1009, plated, where it was described as follows: "1776 Continental Dollar in Pewter Breen-1095 PCGS graded About Uncirculated-58.  CURRENCY.  Glossy medium gray with lighter silvery gray toning in protected areas.  No tin pest or other spots. Nicely struck with excellent eye appeal.  Usual die state with the reverse crack clear and the reverse rotated 140 degrees CCW from normal coin orientation."

PCGS AU-58.  Bowers and Merena Galleries "The Robert W. Schwan Collection," October 26-27, 2000, Lot 8, "Newman-3D, Breen-1095, EG FECIT variety.  Rarity-3...Pewter...fairly early state of the reverse die...Die alignment:70°," unsold

PCGS VF-30.  Ex - Stack's 65th Anniversary Sale, October 17-19, 2000, Lot 8, where it was described (in part) as follows: "Pewter, CURRENCY.  Newman 2-C...a hint of weakness at obverse as seen on the Norweb example of this important variety, reverse rotated dramatically", sold for $7,475.00

"Net F-12".  Ex - Bowers and Merena Galleries' "The Lake Geneva Sale", June 28-29, 2001, Lot 5, illustrated, "246.4 grains...38.1 mm.  Die alignment: 360°, unsold

PCGS VG-10.  Ex - Ira & Larry Goldberg Coins & Collectibles, Inc.'s "Pre-Long Beach Sale", September 23 & 24, 2002, Lot 48, illustrated

Sources and/or recommended reading: