The Houston Daily Post, 29 May 1901, p. 6: the Liverpool William Clarkson, 'who has been visiting his son, W. B. Clarkson, of this city,' leaves for Canada.
Image · dated 29 May 1901 · source: Library of Congress, Chronicling America (public-domain page image).

How it is shown: Article crop; the rest of the page is not held. No retouch.
Keep in mind: Likely: the notice names Mr. William Clarkson of Liverpool, England, and his son W. B. Clarkson of Houston; it does not give a birth year or the relationship to the tree beyond that.
Evidence for
- Houston Daily Post, 29 May 1901: 'Mr. William Clarkson of Liverpool, England, who has been visiting his son W. B. Clarkson...' · the original at Library of Congress, Chronicling America