Who are the people featured on U.S. dollar bills?

All this time, I thought that what was printed on the money was a U.S. President, but on second thought, Benjamin Franklin on the $100 bill is actually not a President.
The law in the United States does not require paper currency to list a President; it only sets one strict condition, which is that the person must already be deceased. As for who is selected, that’s up to the Menteri Keuangan.
I just took a quick look at the people on the dollar bills, just for fun.