Caln Township originally included the territory
  embraced in Caln, East Caln, West Caln, East Brandywine, West Brandywine, a
  part of Valley twp, the borough of Downingtown , and that part of
  Coatesville lying east of the west branch of Brandywine.  It was named
  from the town of Calne in Wiltshire, England, from which some of the early
  settlers came.  In 1702 and about that time surveys were made, extending
  from the Welsh tract on the east to the west branch of the Brandywine on the
  west, mostly confined to the valley.  These surveys were afterwards
  extended northward and northwesterly.
Joseph Cloud, Richard Cloud
  and George Marshall all of Caln were indicted for an assault on Joseph
  Hickman in his house in Caln on 4-6-1709.   In 1714, Peter Taylor was
  constable for Caln, which shows an organization at that date.
The inhabitants of East Caln
  petitioned for a determination of their boundaries in May of 1739, and in
  1744, the boundaries were set for West Caln.
East Caln was reduced in size
  in 1790 by the erection of Brandywine Township which was taken from its northern
  part in that year.  It was again reduced in size in the formation of
  Valley Township on the west in 1853.  In 1859 it was still further reduced by
  the incorporation of the borough of Downingtown.  In 1868 it was again
  divided, the part lying east of the east branch of the Brandywine retaining
  the name of East Caln, and the remainder with the part of Valley Township lying
  east of the borough of Coatesville, taking the original name of Caln.  
  West Caln was slightly reduced in size in 1853, in the erection of valley Township
  on the SE.  From 1790 to 1853 East Caln was a long, narrow township, extending
  from the west branch of the Brandywine to the western line of West Whiteland,
  a distance of over 9 miles.  The greater part of the present townships of Caln
  and East Caln lie in the valley and contain beautiful farmlands , while
  West Caln is more hilly.
Among the early settlers and
  owners of land in East Caln were the names of Baldwin, Cloud, Moore, Parker,
  Taylor, and Vernon; in Caln, the names of Aston, Hung, Lewis, Miller, Pim,
  Parke, Roman, Coates, Bizallion, Musgrove and Mendenhall; in West Caln, the
  names of Sharpless, Swayne, Sinkler, Way, White, Weaver and Dawson.  
  Peter Bizallion was a French trader among the Indians for some time, but
  finally settled here.