Collectible coins, such as the Machins Mills coppers from 1788, represent significant pieces of numismatic history. These coins were produced in New York by a private mint operated by Scottish immigrant Thomas Machin, primarily to address a shortage of currency in the early United States. The Machins Mills coppers are notable for their distinctive design and the inscriptions used, often depicting a helmeted bust on one side and various symbols on the reverse. They are highly sought after by collectors for their historical significance and rarity among early American coinage.