The information provided below came from a cousin (technically a second cousin once removed) that I found on the Internet through his geneology website. Art Michaelis is also a decendent of the William T. Pawson through Joseph Edward Pawson (b. 1873), Inez Pawson Allison (b. 1903), and Elaine Allison Michaelis (b. 1934). Check out his homepage at http://michaelis.us.
The earliest data on the Pawson line begins in London, England in 1774, with the birth of Thomas Pawson. His son, Samuel Pawson, was born in Gravesend, Kent, England in 1799. Samuel gave birth to William T. Pawson in 1837 in Shorditch, London. Shorditch was one of the placed bombed heavily during WW1, so records aren't readily available.
William T. Pawson was a carpenter. The story goes that he took a job as a carpenter's apprentice on a ship and did quite a bit of sailing. In the 1860's he was in Bombay, India working for "The Great Indian Transcontinental Railroad" (or something like that) working as a carpenter building railroad cars; existence of a letter from that company verifies his employment.
By 1870 he had come to America where he met Martha Gardner. She & Wm. T. married in Chicago, Cook County, IL on July 16, 1871. There is no record of the marriage as most of the vital statistics for Chicago burned in the famous Chicago Fire just a few months later. This information came from their divorce papers. Soon after the fire (in 1872) the family moved first to Sutton NE, then to Hastings, NE (or the other way around) and then to Archer, WY.
William's sons Joseph and Harry worked as special agents for the Union Pacific Railroad. By 1926, Harry had married the first of his wives. In 1928, Harry had to stand trial for accidently shooting a homeless man (called "hobos" back in those days) named William Tingle. Although Harry was cleared of wrongdoing, he was asked to leave Cheyenne. During this time, he also obtained a divorce from his first wife, and then he settled in Colorado where he met my grandmother, Sara Watkins. The rest, of course, is history.
I don't have any other information on the origins of this family in England. If you can have any information, please e-mail me. Any information will be appreciated.