On the 1943 steel penny, the mint mark can be found just below the date: "D" represents the Denver Mint, "S" stands for the San Francisco Mint, and no mint mark indicates the Philadelphia Mint.

1943-P wheat pennies could be sold between $0.05 to $0.90 in a circulated condition. You can earn more if you have a steel penny in mint state. In 1943, the Philadelphia Mint used a new die to ...

Certain pennies are more valuable than others. A copper penny from 1943 is valuable. At this time, steel was used to make pennies instead of copper because copper was needed for the war effort.