What this coin looks like (obverse, reverse, mint mark location, special features, etc.): One major variety is the 1819/8 Overdate Error. This Coronet Head Large Cent (Penny) features an 1819 date struck over an 1818 date. This resulted in a small portion of the underlying "8" being visible within the "9" as depicted by the arrows in the example image above.
Coin value chart: Typical coin prices, values and worth in USD based on grade/condition