1811 Dictionary Of The Vulgar Tongue

              A

          DICTIONARY

             OF

BUCKISH SLANG, UNIVERSITY WIT,

            AND

     PICKPOCKET ELOQUENCE

The 1811 Dictionary of the Vulgar Tongue contains lots of interesting items, including the one below.  Was the term used during the War?

ACT OF PARLIAMENT. A military term for small beer, five pints of which, by an act of parliament, a landlord was formerly obliged to give to each soldier gratis.