The "O" mintmark identifies the Mint at New Orleans, LA
No mint mark means it was minted in Philadelphia.
No such thing. There were no dollar coins minted that year.
No mint mark indicates that the coin was minted in Philadelphia.
If there's no mint mark, then it was minted in Philadelphia.
There were no dollar coins minted in 1992.
No mint mark means the coin was minted in Philadelphia.
Not always, no. If it was minted in Philadelphia, then there is no mint mark.
The mint mark on the 1974 Eisenhower silver dollar is located on the reverse side of the coin, just to the right of the eagle's tail. If the coin was minted in Philadelphia, it will have no mint mark. If it was minted in Denver, it will have a "D," and if it was minted in San Francisco, it will have an "S."
Look for the mint mark.
If it has one, it is on the reverse just above DO in DOLLAR.
You are going to have to provide the year the coin was minted - the mint mark 'CC' (Carson City) was minted on multiple year Silver Dollar coins.
No silver coins minted in Philadelphia have a mint mark.