John Alston was born in Scotland on November 10, 1743, the son of George and Isabella Alston. After attending grammar school in Lanark, he moved to Glasgow, where he was an apprentice in a warehouse. In 1759, he sailed to North America, and he lived in Maryland and Virginia until returning to Scotland in 1768. He formed a business partnership with his uncle, also named John Alston, and invested in North American trade before the American Revolution. On June 11, 1772, he married Patrick Craigie ("Patie") of Edinburgh, Scotland (1744-1786). Their children were Anne Hay (b. October 9, 1773), George (May 4, 1775-August 1850), Isabella (b. January 16, 1777), Robert Douglas (October 2, 1778-December 15, 1846), John Thomas (b. April 26, 1780), and Patrick Craigie (May 21, 1782-November 4, 1782). John Alston died on October 31, 1818.