Even though millions of Americans come in daily contact with pennies, nickels, dimes, and quarters, I suspect that very few of us could list the presidents we routinely "handle."
I'll answer your question in short order, but first some little-known background: Article I, Section 8, of the U.S. Constitution authorizes Congress "to coin money." The first federal building constructed under the new Constitution was the U.S. Mint, in Philadelphia, which in the 1790s served as the nation's capital. It is said that President George Washington, who lived just a few blocks from the mint, personally donated some of the silver for the new republic's first coins. That's better than providing a portrait!
Since the 1790s, the U.S. Treasury Department has been responsible for minting coins. I am told that no president's portrait appeared on a coin until the Lincoln penny came out in 1909 to commemorate the centennial of the 16th president's birth. (From the 1790s to the 1890s, however, presidential portraits appeared routinely on peace medals that were given to the Indians.) Traditionally Congress has gotten to choose which presidents are on which coins. Presidents are on at least a half-dozen coins in circulation today. They make up the lion's share -- but not all -- of portraits on circulating coins.
As the old saying goes, there are two sides to every coin. The portrait is on the front or obverse side, everything else on the reverse side. Following are the presidential portraits on the obverse side of currently circulating U.S. coins:
- penny: Abraham Lincoln, looking right;
- old nickel (before March 2005): Thomas Jefferson, looking left;
- new nickel (after March 2005): Thomas Jefferson, looking right;
- dime: Franklin Roosevelt, looking left;
- quarter: George Washington, looking left;
- half dollar: John F. Kennedy, looking left.
In addition to the circulating coins, listed above, you may encounter commemorative coins that are also minted by the U.S. Treasury Department:
- bicentennial dollar: Dwight Eisenhower, looking left (1976);
- half dollar: George Washington 250th commemorative coin (1982);
- dollar: Eisenhower centennial silver dollar (1990);
- dollar: Thomas Jefferson 250th silver dollar (1993);
- five-dollar coin: Franklin Roosevelt gold commemorative coin (1997);
- there were also commemorative coins of George Washington and Dolley Madison minted in 1999; she is, I believe, the only first lady whose portrait is on a coin.
LEFT- VERSUS RIGHT-FACING
On circulating coins until recently, all the portraits but Lincoln's looked left. (Now Jefferson has joined Lincoln in looking right.) Why was Lincoln virtually alone in looking right? The answer has nothing to do with politics. The portrait of our 16th president was based on a plaque by Victor David Brenner done at the beginning of the 20th century. So taken was President Theodore Roosevelt with Brenner's Lincoln that he asked his Treasury secretary to use the design on a coin that was to be put into circulation in 1909, in celebration of the birth of Lincoln 100 years earlier.
MORE COINS, MORE PRESIDENTS?
Collectors may get a new burst of coins to collect. Congress is currently considering minting dollar coins to commemorate all our past presidents. This follows the Mint's wildly successful state quarter program, which has generated $5 billion in revenue and turned some 140 million Americans into coin collectors. The coins would be minted at a rate of four presidents per year, starting with George Washington. Only sitting presidents would be excluded.
THE STORIES BEHIND THE PORTRAITS
There is a story about the presidential portraits on each of our coins. Following is from the Website of the U.S. Mint:
The presidents that appear on the obverse (front) side of our circulating coins were all selected by Congress in recognition of their service to our country. However, they were chosen under slightly different circumstances.
Designed by Victor Brenner, the Lincoln cent was issued in 1909 to commemorate the 100th anniversary of Abraham Lincoln's birth. Felix Schlag's portrait of Thomas Jefferson, which began to appear on the obverse side of the nickel in 1938, was chosen in a design competition among some 390 artists.
The death of Franklin Roosevelt prompted many requests to the Treasury Department to honor the late president by placing his portrait on a coin. Less than one year after his death, the dime bearing John R. Sinnock's portrait of Franklin D. Roosevelt was released to the public on FDR's birthday, January 30, 1946.
The portrait of George Washington by John Flanagan, which appears on quarters minted from 1932 to today, was selected to commemorate the 200th anniversary of our first president's birth.
The assassination of President John F. Kennedy generated such an outpouring of public sentiment that President Lyndon Johnson sent legislation to Congress to authorize the Treasury Department's new 50-cent pieces. Bearing the portrait designed by Gilroy Roberts, the first Kennedy half-dollars were minted on February 11, 1964.
(Question from Lupe M. of Fresno, CA)
 See the U.S. Mint Website at http://www.usmint.gov/about_the_mint/mint_history/
 Jennifer Brooks, "Presidents May Replace Sacagawea on Some $1 Coins," Lansing State Journal, April 27, 2005, p. 1A.