[mgc1122]

You know the funny part about the drinking rumors? They almost all were started by jealous Yankee army officers. Grant had similar drinking habits to many of his brother bluecoats ... to his credit, he didn't drink while planning a battle or near his wife. But otherwise, as stated earlier, when he started, he went from sober to slobbering drunk pretty quick.

[Pharmboy]

The fact that he was (at times) incapacitated by alcohol makes him an alcoholic, drunk, sot or whatever other term you would like to use to describe that aspect of his persona...