re: John Houston, b.1705, Londonderry, N. Ireland (any christening record in the CD "Register of Derry Cathedral 1642-1703" ? ) m. Martha Stewart, bc.1721 (Leacock Twp, Lancaster Co PA ?) had son, Dr. John Houston, b. 1743 Pequea Valley, Lancaster Co PA, went to Glasgow, Scotland c.1761, d. 5 June 1809, Columbia, Lancaster Co, PA, m. 17 June 1773 at Wrightsville, York Co PA to Susanna Wright b. 24 Aug 1752, Wrightsville,
UNIVERSITY OF GLASGOW. no.2045JOHANNES HOUSTON(Matric. AD1761) filius natu maximus (eldest son of) Joannis (John) Coloni (Colonel ?) et (and) Mercatoris (merchant) in Pensylvania, Americae Provincia
Another source notes : Born in 1743. Graduate in Surgery of the University of Pennsylvania, 1769. Died at Wrightsville, York County there, 5th June, 1809. Grandfather of Henry Howard Houston, who founded Howard Houston Hall in the grounds of the University of Pennsylvania.
And another source notes : Dr. John Houston, b. in 1743 ; d. 5 June 1809. grad. at Edinburg College, Scotland, 1766; studied medicine with Dr. Shippen, of Philadelphia ; 1790 appointed by Gov Mifflin as Justice for Hempfield township, Lancaster Co., Pa.