The Collaborative International Dictionary of English v.0.48:

Chapman \Chap"man\, n.; pl. Chapmen. [AS. ce['a]pman; ce['a]p
   trade + man man; akin to D. koopman, Sw. k["o]pman, Dan.
   ki["o]pmand, G. kaufmann.f. Chap to cheapen, and see
   Cheap.]
   1. One who buys and sells; a merchant; a buyer or a seller.
      [Obs.]
      [1913 Webster]

            The word of life is a quick commodity, and ought
            not, as a drug to be obtruded on those chapmen who
            are unwilling to buy it.              --T. Fuller.
      [1913 Webster]

   2. A peddler; a hawker.
      [1913 Webster]

U.S. Gazetteer (1990):

Chapman, KS (city, FIPS 12550)
  Location: 38.97176 N, 97.02064 W
  Population (1990): 1264 (524 housing units)
  Area: 1.3 sq km (land), 0.0 sq km (water)
  Zip code(s): 67431
Chapman, NE (village, FIPS 8780)
  Location: 41.02286 N, 98.15965 W
  Population (1990): 292 (130 housing units)
  Area: 1.2 sq km (land), 0.0 sq km (water)
  Zip code(s): 68827
Chapman, PA (borough, FIPS 12656)
  Location: 40.75918 N, 75.40148 W
  Population (1990): 254 (92 housing units)
  Area: 1.0 sq km (land), 0.0 sq km (water)