There is no "E" mint mark on any US coin, the 1928 Peace dollar can have only one mint mark an "S" which is on the reverse just above the tip of the eagles tail. If there is no "S" the coin was struck in Philadelphia, if it has a "S" the coin was struck in San Francisco. Please look at the coin again because the difference in value of the coin is very large depending on which mint the coin came from, with a "S" mint mark in the lowest grade of G-4 it has a value of $18.00 with no mint mark in the same grade value is $293.00
It's notoriously difficult to value a coin sight unseen. Take it to a dealer.
That said ... "E" on it? What does that mean? "E" is not a mint mark that has ever been used for US Coins (though if it's a "dollor" it may not be a US coin).
E isn't a mint mark for any mint. If this E is on the reverse (tails side), near the words "Pluribus Unum," then it's actually the first word of the national motto "E Pluribus Unum."
The Denver mint did not strike any silver dollars in 1928. You may have a 1928-S where the S is indistinct. This coin is worth $20 to $30 depending on condition.
To clarify things, the US Mint only makes coins. Bills are printed by the Bureau of Engraving and Printing.Please see the question "What is the value of a 1928 US 1 dollar silver certificate" for more information.
1928 would make it a Peace dollar. The mint mark is located on the reverse (tails) side, just below the word "one."
If the 1928 Peace dollar has no mint mark, circulated coins have retail values of $275.00-$430.00 depending on the grade.
If the 1928 Peace dollar has no mint mark, circulated values are $290.00-$450.00 depending on the grade
Circulated coins are $25.00-$90.00 Mint State examples are $150.00 or more
The Philadelphia issue (no mintmark) in the circulated grades is $275.00-$445.00, Mint State examples are $525.00 or more.
If you mean a 1928 Peace dollar with No mint mark It's the key date to the series the value in VF-20 is $475.00. I suggest you take it to a coin dealer, because I have seen many 1928 S mint coins with the mint mark removed.
1922 silver dollar with closed eagle wings
No D's in 1928. The coins were only struck in Philadelphia and San Francisco. The S coins run from $30.00 to $70.00 in circulated grades.
About $107.50.
They didn't mint 1920 US silver dollars.