Silver Dollars
Silver dollars are some of the most collectible United States dollar coins and boast some of collectors' favorite coin designs. Of these, the Morgan dollar -- minted from 1878-1921 -- is perhaps the most famous, featuring a portrait of Lady Liberty on the obverse and an eagle on the reverse. The Peace dollar was the last 90-percent silver dollar minted for general circulation, and it was minted until 1935. The Mint began making silver dollars again in 1971, using a design featuring President Dwight D. Eisenhower. However, only Eisenhower dollars made for special collectible sets included silver, and those coins were minted from 40-percent silver rather than the 90-percent alloy of older silver dollars.
Gold Dollars
The discovery of gold in California in 1848 led to a gold rush. As a result of the proliferation of the precious metal, the United States Mint struck gold dollar coins from 1849 to1889. The gold dollar is a tiny coin, weighing approximately 1.6 g -- about 0.8 g less than a dime. The Mint changed the design of the gold dollar twice, resulting in three different designs: the Liberty Head, the Small Indian Head and the Large Indian Head.
Silver Eagle
The Silver Eagle is the modern version of the silver dollar. Though it is legal tender and does say "One Dollar" on the reverse, the coin is 1 oz. of nearly pure silver and has precious metal content worth many times more than its face value. Silver Eagle coins are sold to collectors and precious metal speculators, who buy them rather than plain silver bullion because of the beautiful design and the fact that they are legal tender.
Modern Dollar Coins
In 1979, the United States Mint changed the form factor of the dollar coin to the smaller one still in use today with the Susan B. Anthony dollar. The dollar was not well received by the public, who regarded it as being difficult to differentiate from the quarter due to its similar size, color and reeded edges. The Mint produced the Susan B. Anthony dollar from 1979 to1981, and again in 1999 before replacing it with the Sacagawea dollar, also called the Golden Dollar. The Sacagawea dollar does not contain any gold. Rather, the coin is minted from copper and has a brass cladding on the outside.
Commemorative Dollars
The United States Mint frequently releases commemorative coins instead of or alongside existing coin designs. Beginning in 2007, the Mint began releasing commemorative dollar coins with the same brass cladding as the Sacagawea dollar. Each coin features the face of a different United States president. The Mint will release coins commemorating four new presidents each year until the end of the program in 2016.