Little is known about Admittance, an American merchant brig operating along the California coast during the Mexican War. The United States sloop of war Portsmouth seized this vessel on 8 April 1847 at San Jose, Calif., for "trading with the enemy." Comdr. John B. Montgomery, Portsmouth's, commanding officer took the prize into the Navy; and, under the command of Lt. Joseph Warren Revere, she served until 6 May 1848. No record of her fate thereafter seems to have survived.