The US Mint did not produce any coins with a mintmark from 1965-1967. Silver was also removed from coins during this time, and proof sets and mint sets were not produced either. It wasn't until 1968 that mintmarks, proof sets, and mint sets returned to normal. See why 1965 coins, 1966 coins, and 1967 coins are different, and what's so unique about 1968 coins.
The US Mint did not produce any coins with a mintmark from 1965-1967. Silver was also removed from coins during this time, and proof sets and mint sets were not produced either. It wasn't until 1968 that mintmarks, proof sets, and mint sets returned to normal. See why 1965 coins, 1966 coins, and 1967 coins are different, and what's so unique about 1968 coins.