The American Coins are being minted for more than 3 centuries now.
Mintage is the actual number of coins reported as produced in a given year for a particular coin. A Mint Mark is the initial or abbreviation of the Mint producing the coin and is usually engraved on the reverse or the value side.
The following mints produced coins and the mint marks seen are :-
Philadelphia - No Mint Mark , (P – 1942-45 Wartime Nickels only)
San Francisco – S
Denver - D , It produced uninterrupted coinage during each year of the Morgan series (1878-1904 and 1921) and Peace series (1921-1928, 1934-1935), except for the 1921 Peace dollar.
no Morgan dollars were struck at Denver until the Morgan series resumed briefly for 1921. The Denver mint began producing the Peace silver dollar coin in 1922
New Orleans – O
Carson city – CC , The Carson City mint, in Carson City, Nevada, produced gold and silver coins from 1870 to 1893 dollar coins from silver mined in the area.
Charlotte – C (on gold coins only)
Dahlonega – D (on gold coins only from 1828-1861)