The year was 1974 for circulating coins. Proof coins still have the "S" mint mark.
Technically speaking, the United States never issued "pennies" - unlike Great Britain, they are referred to as "cents."
1974 was the last year the San Francisco Mint issued Lincoln cents for general circulation.
The majority of Australian Pennies with no Mint Mark were minted at the Melbourne Mint. The Sydney Mint was closed in 1926. All other Australian Pennies will have one of a variety of Mint Marks on them indicating that they were either minted at the Perth Mint, or a variety of foreign Mints.
The "D" Mint Mark identifies the Denver Mint. There were no one cent coins minted in Denver in that year; they were all made either in San Francisco ( S Mint Mark), or in Philadelphia ( no Mint Mark). Double-check your coin with a strong magnifying glass.
Since 1968 San Francisco has struck proof coins, including cents, that all carry the "S" mint mark. However they no longer make coins for circulation. San Francisco struck pennies nearly every year from 1908 to 1955. The mint was deactivated from 1956 to 1964. In 1965 it started producing circulation coins and Special Mint Sets during the great coin shortage but none of these carried a mint mark. The S mint mark was returned to circulating cents minted from 1968 to 1974, but those were the last ones minted up to the present.
In 2011, the U.S. Mint produced 4,938,540,000 pennies.
On a 1948 penny, the "Y" mint mark, which indicates that the coin was produced in Philadelphia, is located on the reverse side of the coin, specifically to the right of the wheat stalks. However, it's important to note that pennies minted in Philadelphia during that year do not have a mint mark at all. Only those minted in Denver will have a "D" mint mark, while those from San Francisco will have an "S."
It was made at the Denver Mint. Cents made at Philadelphia (and very occasionally, West Point) don't have mint marks. These amount to about half of the cents made every year, and are the only Philadelphia coins since 1980 that don't have a P mint mark. Modern proof cents and older circulating cents also come from San Francisco which uses an S mint mark.
The last year was 1958.
You do not specify the pennies of which country. The mint of the country concerned will decide the requirements for the year and publish their minting figures for the year in their next Annual Report.
There was a brief period of 1965-67 when no U.S. coins had any mint marks. However, since 1968, D and S mint marks returned, and P was added to most coins in 1980. Philadelphia pennies still lack a mint mark, but Denver ones are marked with D, and proofs from San Francisco have the S.
The last year that wheat pennies were minted was 1958.
The last year for wheat pennies was 1958.