The 1920 Maine was minted to commemorate the 100th anniversary of Maine's statehood. The mintage of this issue was a relatively high 50,028 pieces and many were saved. The original issue price was $1.00. Today, the Maine is one of the more available "early", i.e. pre-1930, silver commemorative issues. It is only a little bit rarer than the 1936 Robinson and 1935 Connecticut.
The average grade for a Maine is MS63 to MS65. There are some circulated examples known. Superb MS66 specimens can be found, but MS67 examples are very rare. Strike is not a problem with this issue but many Maines have numerous scratches and abraisions. Luster can be frosty and white.