Obsolete Coins

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.
Half Cent
Value: 0.005 U.S. dollar
Mass: 6.739 g (1793-1795) - 5.443 g (1795-1857)
Diameter: 23.5 mm
Thickness: ? mm
Edge: lettered (1793,1797) plain (1794-1857) reeded (1797)
Composition: 100% Cu
Large Cent
Value: 0.01 U.S. dollar
Mass: ? g
Diameter: varied between 27mm and 29mm
Thickness: ? mm
Composition: 100% Cu
Two Cent
Value: 0.02 U.S. dollars
Mass: 6.221 g
Diameter: 23.00 mm
Thickness: ? mm
Edge: plain
Composition: 95% Cu, 5% Zn & Sn
Observe: Shield
Reverse: Wreath
Three Cent
Value: 0.03 U.S. dollars
Composition: silver and copper/nickel
Half Dime
Value: 0.05 U.S. dollars
Composition: silver
Twenty Cent
Value: 0.20 U.S. dollar
Mass: 5 g
Diameter: 22 mm
Thickness: 1.55 mm
Edge: plain
Composition: 90% Ag, 10% Cu
Obverse: Liberty Seated
Reverse: Eagle
Trade Dollar (some modern commemoratives are minted in this denomination)
Value: 1.00 U.S. dollars
Mass: 27.2 g
Diameter: 38.1 mm
Thickness: 3.1 mm
Edge: Reeded
Composition: 90% Ag, 10% Cu
Quarter Eagle
Value: 2.50 U.S. dollars
Composition: gold
Three Dollar
Value: 3.00 U.S. dollars
Composition: gold
Value: 4.00 U.S. dollars
Mass: 7.00g
Diameter: 22.0 mm
Thickness: 1.52 mm
Edge: Reeded
Composition: 6.00g Au, 0.30g Ag, 0.70g Cu
Observe: Liberty bust
Reverse: Five-pointed star
Half Eagle (some modern commemoratives are minted in this denomination)
Value: 5.00 U.S. dollars
Composition: gold
Eagle (some modern commemoratives are minted in this denomination)
Value: 10.00 U.S. dollars
Composition: gold
Double Eagle
Value: 20.00 U.S. dollars
Composition: gold
Half Union (Commemorative only, California territorial gold, pattern piece)
Value: 50.00 U.S. dollars
Composition: gold