Where is the mint mark on an 1889 liberty dollar coin?

I'm not certain which coin you are wanting to know about. In 1889 there were no coins to my knowledge called "liberty dollar". However, there was a gold dollar minted that year which was minted in Philadelphia and therefore carries no mint mark. None were minted anywhere else. Also in 1889 there was a silver dollar minted called "Morgan Dollar" . The mint mark on this one is located below the wreath on the reverse side of the coin. These were minted in Carson City, Nevada and carried a "CC" mint mark: New Orleans, Louisiana and carried an "O" mint mark: San Francisco, California and carried an "S" mint mark: Philadelphia, Pennsylvania and carried no mint mark at all.