1815 is the only year U.S. one cent coins (pennies) were not made.
1860 The last copper pennies were made in England, and the same year the first bronze pennies were made.
The last year for 100% pure copper cents was 1857.
These pennies are called "Wheat Pennies". They were last made in 1958.
1982
The last year wheat cents were made was in 1958.
For a specific answer, you need to ask about a specific year.
There are no exact records of the number of copper pennies made in 1943. It was about 40. Most pennies that year were made of steel.
1982
Pennies are made of zinc and other alloys with a copper coating, pennies made before 1964(or around this year) they were made of just copper. What you see on a penny is not rust but corrosion of the copper coating.
A 1957 penny is made of bronze, an alloy of 95% copper with the rest being varying amounts of tin and zinc. There were over 1 billion pennies made in that year, with all of them being made of bronze.
All of them were supposed to be made of steel, however there were a few copper coins accidentally struck that year. Its extremely rare to come across copper pennies from that year.
The materials used to mint pennies has changed. Originally, pennies were made of almost pure copper. Today, British pennies are made of nickel/steel blanks coated in copper, and US "pennies" (actually cents) are made of zinc blanks coated in copper.