The Collaborative International Dictionary of English v.0.48:

Acton \Ac"ton\, n. [OF. aketon, auqueton, F. hoqueton, a quilted
   jacket, fr. Sp. alcoton, algodon, cotton. Cf. Cotton.]
   A stuffed jacket worn under the mail, or (later) a jacket
   plated with mail. [Spelled also hacqueton.] [Obs.]
   --Halliwell. Sir W. Scott.
   [1913 Webster]

U.S. Gazetteer (1990):

Acton, CA (CDP, FIPS 212)
  Location: 34.48278 N, 118.18247 W
  Population (1990): 1471 (587 housing units)
  Area: 12.0 sq km (land), 0.0 sq km (water)
  Zip code(s): 93510
Acton, IN
  Zip code(s): 46259
Acton, MA
  Zip code(s): 01720
Acton, ME
  Zip code(s): 04001
Acton, MT
  Zip code(s): 59002