William Bartholomiew (Barclay) Masterson was born in Henryville, county of Iberville , Provience of Quebec, Canada, on November 26, 1853. His Christian name actually being William Bartholomiew (with the French spelling ie) Masterson. He did not believe Bartholomiew was a masculine name, so he changed it to Barclay; although he never really used it. Bat was the second of seven children of Thomas and Katherine (nee:) McGurk. His siblings were: Ed, the oldest, James (1855), Nellie (1857), Thomas Jr.(1858), George Henry(1860) and Emma or Minnie as she was called by family(1862).
The family left Canada, when Bat was about 8, and traveled through NY, Illinois, and finally settling on an eighty-acre tract of land in Grant Township, Sedgwick, KS, about 14 miles Northeast of Wichita, KS. in June 1871. When Bat was about 17, he, brother Ed and a neighbor, Henry Raymond headed for the buffalo hunting fields just North of Wichita, where they were employed as hide skinners. As the season ended, Bat, Ed and Raymond went to Wichita and began work laying track bed for the Atchison, Topeka & Santa Fe railroad to what was then camp Dodge, near then Buffalo City. This was later changed to, Dodge City. Upon completion of the "job", Bat, Ed and Raymond were told by Ritter, the supervisor, that he had to return to Wichata to obtain their full pay. The trio remained in Dodge City waiting for payment for their work, which never came. Ed and Raymond returned to Sedgwick. Bat remained and returned to the buffalo fields. It was here that he met his life long friend, Wyatt Earp,who taught him more about life and how to gamble. When Bat returned to Dodge City, he heard Ritter was returning to Dodge on the train. Bat boarded the train before it reached it's stop and at gunpoint made the supervisor pay him his $150. Bat then went into Dodge City and bought drinks for all who were in attendance at the saloon.