He was the son of John Clark, a thread manufacturer in Paisley, where he was born on 9 August 1823.
He was educated at Paisley grammar school, and in 1840 was sent the firm of Kerr & Co. of Hamilton, Ontario.
[2] In 1851 Clark gave up his partnership to go into with his brother-in-law, Robert Kerr, as a thread manufacturer.
To extend the business he went in 1856 to the United States, and to avoid the tariffs the firm in 1864 established a factory at Newark, New Jersey.
[2] By his will Clark left £20,000 for scholarships at Glasgow University, and £20,000 to build a town hall in Paisley.