Well at the business strike cents from Philadelphia don't have mintmarks on them. (except for 2017-P cents)

Just a normal cent from that year, that is not a proof coin. It is a proof cent that since 1968 that if it were missing the mintmark, then that would be interesting.
All the other denominations from Philly didn't have mintmarks until 1980, then the 'P' was added to them. But cents didn't have a mintmark from Philly, except for the 2017-P cents.

Just a normal cent from that year, that is not a proof coin. It is a proof cent that since 1968 that if it were missing the mintmark, then that would be interesting.
All the other denominations from Philly didn't have mintmarks until 1980, then the 'P' was added to them. But cents didn't have a mintmark from Philly, except for the 2017-P cents.





















