from Google AI:
"
2009 Special Issue Copper Pennies
In 2009, the U.S. Mint released a special series of Lincoln pennies to commemorate the bicentennial of Abraham Lincoln's birth and the centennial of the Lincoln cent. This series included four different designs, each representing a significant phase of Lincoln's life.
Designs:
Birth and Early Childhood
Formative Years
Professional Life
Presidency
Among these, there were two types of 2009 pennies:
Circulation Coins: Made from the standard copper-plated zinc composition.
Collector's Coins: Some special uncirculated sets included pennies made of 95% copper and 5% tin and zinc, similar to the original Lincoln cents.
These collector's versions are often referred to as "copper" pennies, but they were not intended for general circulation."