None of them will have mint marks.
The US did not mint any half dollars dated 1800.
The Related Link below has a list of dates, mint marks, and mintage totals.
The lack of a mint mark indicates that the coin was minted in Philadelphia.
No. Silver dollars minted at Philadelphia did not carry mint marks. Mint mark positions are: Seated Liberty dollars - under the eagle Morgan dollars - above the DO in DOLLAR Peace dollars - between the word ONE and the eagle's tail feathers. Mint mark letters are: blank = Philadelphia D = Denver S = San Francisco O = New Orleans CC = Carson City Dollars weren't minted every year at every mint, so there are many gaps in the series.
1-15 dollars.
12 so far if you include different mint marks 36.
Assuming no mint marks $9.00-$60.00 in average circulated condition.
The Related Link below has a list of dates, mint marks, and mintage totals.
Retail values for Mint State coins are MS-60 $39.00/ MS-61 $48.00/ MS-62 $55.00 most uncirculated 1884 Morgan dollars fall into these grades.
The value of a 1800 silver dime depends on the condition of the coin. In mint condition this coin sells for as much as 2000 dollars as of 2014.
It's called a mint MARK, not a mint "marker", and is a small letter indicating the location of the mint where the coin was struck. However, all 1856 silver dollars were minted at Philadelphia, which did not use the P mint mark in those days, so there will not be any 1856 dollars with mint marks. Other dates of Liberty Seated dollars may have a small S (San Francisco) or O (New Orleans) located below the eagle on the back of the coin. You can find a list of mint marks and positions for all circulating U.S. coins at www.coinfacts.com.
The mint mark position on all Peace dollars is near the word ONE on the back. No mint mark = Philadelphia D = Denver S = San Francisco