As with most claims such as this, there is truth in there somewhere, but it is perhaps not as extreme as we think. Grant did partake in alcohol and was actually forced to resign as a Captain in 1854. This can be attributed to the loneliness Grant experienced being stationed in California, very far away from his family in Ohio. He was reported as being drunk on duty. At that point, it is believed that he went sober for nearly a decade in an attempt to straighten his career up. He rejoined the Army in 1861.

However, it is also believed that Grant became a binge drinker throughout the Civil War. While this primarily comes from anecdotal evidence, Grant's prior history with alcohol and the frequency in which men drank during this period suggests it may be true.