If it has one it's just above the eagles tail on the reverse.
42cents
About $150.
"DO" isn't a mint mark. The mint mark on a silver dollar for that year is on the reverse (tails) side, just above the letters "do" in the word "dollar."
There's no "MD" mint mark on any US coin. The mint mark on a Peace dollar is near the word ONE on the back: No mint mark = Philadelphia D = Denver S = San Francisco Please see the Related Question for more.
If there's no mint mark, then it was minted in Philadelphia.
100
Please see the Related Question
The U.S. did not issue any silver dollars in 1918, so that half of the question can't be answered. As for a 1922 Peace dollar, many of these were saved so they're currently worth more for their silver content than as collector's items. Regardless of mint mark, one would retail at roughly $13 or $14.
If it has one it's just above the eagles tail on the reverse.
There has never been an L mint mark on any U.S. coin. You may be looking at an intertwined "A F" which is the monogram of the designer Anthony de Francisci
About $150.
42cents
"DO" isn't a mint mark. The mint mark on a silver dollar for that year is on the reverse (tails) side, just above the letters "do" in the word "dollar."
There's no "MD" mint mark on any US coin. The mint mark on a Peace dollar is near the word ONE on the back: No mint mark = Philadelphia D = Denver S = San Francisco Please see the Related Question for more.
One Dollar
Circulated 1922's are only valued at $16.00-$20.00, so $18.00 maybe?