The first commemorative coin was issued in 1892 for the Columbian Exposition. About 2.5 million were minted and sold for a dollar a piece. They were less popular than expected, and so most were later dumped at face value.
In the US, the minting of commemoratives has been spotty. An artificial distinction is made between the "classic" era (1892 to 1954) and the modern era (starting in 1982).
I currently have discussion about the following commemoratives:
Classic Commemoratives:
Columbian half dollar (1892 & 1993)
Old Spanish Trail (1935)
Washington/Carver (1951 to 1954)
Modern Commemoratives
The modern era began in 1982 with the minting of the George Washington Commemorative, a coin which garnered so little numismatic interest or value, that I have not yet written about it. I do, however, have information on the following:
Buffalo dollarsFirst Spouse Coins
Bald Eagle Coins
Lincoln Dollars
Braille dollars
Columbus coins (1992)
Boy Scout Dollars (2010)
US Marshals Coins (2010)