"Civil War brews not only adjusted attitudes, but also helped fund the war through a dollar-a-keg excise tax. A levy on beer, spirits, tobacco, and other items-as well as the nation's first federal income tax-were created by President Lincoln and Congress to finance the war."
In the same article it mentions that one can purchase a beer called "Antietam Ale" on tap at Brewer's Alley in Frederick, Md. It is supposed to taste like what soldiers would have had 150 years ago. A brew called "Proclamation Porter" is scheduled to be released in January.