Who invented the penny?

Answer 1

No one person "invented" the penny.

Instead, the Romans imitated the Greeks by minting the silver denarius, which evolved in various forms into the Anglo-Saxon Sceat which were small, thick silver coins. Starting around 750 AD, the Sceat started being replaced by broad, thin silver coins to imitate those circulating among the Carolingians on the continent. These were the first real "pennies" which, aside from minor changes in design and weight, remained the same until the advent of milled (machine made rather than hand struck) coinage starting with a handful of trial pieces and small runs in the mid to late 1500s and starting in earnest by the end of the 1600s when the old method of hammering coins finally was fully replaced by milled coinage. Silver pennies were pretty much the only true pennies issued by the Crown (farthings and half-pennies were struck in copper and tin irregularly) until 1797 when the cartwheel penny was struck by the Soho Mint. After many issues of varying sizes, the size of copper pennies remained constant from the reign of George IV until 1860 during the reign of Queen Victoria where they were reduced in size and weight and were struck in bronze. These coins were struck until decimalization (the last struck bore the date of 1970 and were released in proof sets only, the last ones struck for circulation were dated 1967), a "new penny" was introduced for decimalization in 1971 and has remained ever since.

For the US, the penny was introduced in 1793 (the individual colonies had issued their own coinage prior to this) and was about equal to a British half penny. These pennies were about the size of a US half dollar and remained the large size until 1857 when they were replaced by the smaller sized flying eagle cent which in 1859 was replaced by the Indian Head Cent which was replaced by the Lincoln Wheat cent in 1909.