United States coinage was first minted by the new republic in 1792. New coins have been produced every year since then and they make up a valuable aspect of the United States currency system.

Today circulating coins exist in denominations: $0.01, $0.05, $0.10, $0.25, $0.50, and $1.00. Also minted are bullion and commemorative coins. All of these are produced by the United States Mint.

The coins are then sold to Federal Reserve Banks which in turn are responsible for putting coins into circulation and withdrawing them as demanded by the country's economy.

Current coinage

Today four mints operate in the United States producing billions of coins each year. The main mint is the Philadelphia Mint which produces circulating coinage, mint sets and some commemorative coins.

The Denver Mint also produces circulating coinage, mint sets and commemoratives. The San Francisco Mint produces regular and silver proof coinage. The West Point Mint produces bullion coinage (including proofs). Philadelphia and Denver produce the dies used at all of the mints.

The proof and mint sets are manufactured each year and contain examples of all of the year's circulating coins. These and the other non-circulating coins can be purchased directly from the US Mint.

One Cent
Obverse: President Abraham Lincoln
Reverse: Lincoln Memorial
Diameter: 19.05 mm
Thickness: 1.55 mm
Mass: 2.5 g
Composition: 97.5% zinc core, 2.5% copper plating
Date of first minting: 1959
Common reference: Wheat Penny, Penny, Cent
Five Cents
Obverse: President Thomas Jefferson
Reverse: Monticello
Diameter: 21.21 mm
Thickness: 1.95 mm
Mass: 5 g
Composition: 91.67% copper, 8.33% nickel
Date of first minting: 2006
Common reference: Nickel
One Dime (Ten Cents)
Obverse: Franklin D. Roosevelt
Reverse: Olive branch, torch, oak branch
Diameter: 17.91 mm
Thickness: 1.35 mm
Mass: 2.268 g
Composition: 91.67% copper, 8.33% nickel
Date of first minting: 1946
Common reference: Dime
Quarter Dollar
Obverse: George Washington
Reverse: Bald eagle
Diameter: 24.26 mm
Thickness: 1.75 mm
Mass: 5.670 g
Composition: 91.67% copper, 8.33% nickel
Date of first minting: 1932 (resumed in 1977)
Common reference: Quarter
Half Dollar
Obverse: John F. Kennedy
Reverse: Seal of the President of the United States
Diameter: 30.61 mm
Thickness: 2.15 mm
Mass: 11.34 g
Composition: 91.67% copper, 8.33% nickel
Date of first minting: 1964 (resumed in 1977)
Common reference: Half dollar, 50-cent piece
One Dollar
Obverse: Sacagawea with child
Reverse: Eagle in flight
Diameter: 26.5 mm
Thickness: 2 mm
Mass: 8.1 g
Composition: 88.5% copper, 6% zinc, 3.5% Manganese, 2% nickel
Date of first minting: 2007
Common reference: Gold(en) dollar

Note: It is a common misconception that "eagle"-based nomenclature for gold U.S. coinage was merely slang. This is not the case. The "eagle," "half-eagle" and "quarter-eagle" were specifically given these names in the Coinage Act of 1792. Likewise, the double eagle was specifically created as such by name ("An Act to authorize the Coinage of Gold Dollars and Double Eagles", title and section 1, March 3, 1849).

Some modern commemorative coins have been minted in the silver dollar, half-eagle and eagle denominations.

The law governing obsolete, mutilated, and worn coins and currency, including denominations which are no longer in production (i.e. Indian cents) can be found in 31 USC 5120.