Machin's Mills coins are a series of counterfeit coins produced in the late 18th century in what is now New York. The most notable among these is the 1772 variety, which imitates colonial currency and features designs that resemble official coinage, particularly those of the United States. These coins are primarily made of copper and were used to circulate in local commerce, often deceiving the populace due to their resemblance to legitimate currency. Collectors highly value Machin's Mills coins for their historical significance and the insights they provide into pre-Revolutionary America.