Up till 1979/80, all coins made in Philadelphia, except for WW2-era nickels, did not carry mint marks. Also, regardless of date, all cents made in Philadelphia or West Point do not carry mint marks.
So if your coin is older than 1980 it is from Philadelphia. If it's a cent, it's from one of those 2 mints but it's not possible to tell which one.
Other exceptions:
Between 1965 and 1967, no coins had mintmarks. The US moved from silver coinage to copper-clad in 1965 and was trying to prevent shortages due hoarding as the new coins were introduced.
From 1973 to 1986, the West Point, NY, mint produced cents without mintmarks to meet high demand for the denomination. There is no way to differentiate cents produced in West Point from those produced in Philadelphia.
West Point also produces some proof, commemorative and bullion coins which do not always have the "W" mintmark.
Additionally, there are errors of one kind or another. The most famous example is that of the 1922 "Plain" cent. These coins were produced in Denver but the "D" mintmark got clogged up over time on some of the dies. Some coins have a very dim mintmark and others have none at all. The latter are quite valuable.
No US coin bears an "F" mint mark
If there isn't a mint mark on a US coin, usually it means that such a coin was minted in Philadelphia.
No mint mark indicates that it was minted in Philadelphia. The coin is worth exactly one cent.
The "P" Mint mark was not used on any US $1 coin until 1979. Your coin was struck in Philadelphia
On an US coin it can mean "cents" or it can be the mint mark of the Charlotte Mint, which existed only from 1838 to 1861.
The letter is known as the mint-mark and tells where the coin was made. A coin having a P mint-mark (or no mint-mark on some coins) was made in Philadelphia, a coin having an S Mint-mark was minted in San Fransisco, a coin with a D mint-mark was minted in Denver.
The mint mark on the US 1849 One Dollar coin is located on the reverse [tails] side of the coin under the wreath. There will be a "C" for Charlotte, North Carolina mint ; a "D" for Dahlonega, Georgia ; an "O" for New Orleans, Louisiana. The absence of a mint mark indicates the coin was struck at the Philadelphia, Pennsylvania mint.
Any US coin without a mint mark was minted in Philadelphia, because for a while, it was the only mint.
Normally you have to know a coin's denomination to locate the mint mark because it can be in different places. Also, Philadelphia did not use a mint mark on most coins until 1980 so it's very possible your coin doesn't have a mint mark. Once you know the denomination you can check a site such as www.coinfacts.com that shows the mint mark locations for all US coins.
YES I have one.
The mint mark for the 1909 Half Eagle is located on the reverse {eagle} side of the coin just to the left of the arrow points.
I'm assuming you mean the mint-mark? The mint-mark shows which branch of the US mint created the coins, if there is a P mark (or no mintmark on some coins) the coin was minted in Philadelphia, a D mark signifies Denver, an S mark shows the coin was from San Fransisco and a W mark is from the West Point Mint.