The following Q&A is excerpted from Clifford Mishler’s Coins: Questions & Answers:
Q: Why is there such a multitude of varieties of the U.S. silver dollar series from 1794 to 1803?
A: During the 1790s and the early 1800s, U.S. coinage dies for all denominations were individually hand-engraved, with the inevitable result that no two dies of any design type were truly identical. The difficulty of striking the large coin also resulted in excessive die wear and breakage, so on the average significantly fewer dollar coins could be successfully struck from a die than, say, quarters. During this period, the dollar was the only silver coin minted in appreciable quantities. Thus, the relatively short-lived hand-crafted dies, coupled with an early emphasis on dollar production, could only translate into infinite die varieties.
Q: Why was the coinage of silver dollars suspended from 1804 through 1839?
A: Speculators, upon learning that in the West Indies the U.S. dollar was accepted at par with the heavier Spanish dollar, shipped the U.S. dollars to the Indies to be exchanged for their heavier counterpart. The Spanish dollars were then turned in to the Philadelphia Mint as bullion to be re-coined into a greater quantity of the lighter U.S. dollar. This abuse prevented the U.S. dollars from circulating and caused President Jefferson to suspend minting of the coin in 1804, although he had no constitutional authority to do so.