Two brothers, William and John were a great influence to the industry of Oshawa.  The Cowans were the next family in line after the Gibbs family that began to decline.  Their business enterprises began with a general store in Toronto, and Prince Albert (near Port Perry) but they moved to Oshawa in 1866.  Before they had moved their store to Oshawa, they had befriended A.S. Whiting. He eventually convinced John, an expert accountant, to manage the Cedar Dale Works.  While there, John was brought into the firm and it became Whiting and Cowan.  Another friend of theirs, F.W. Glen who managed the Joseph Hall Works, suggested that they build a plant that manufactured malleable iron, as malleable iron could only be bought from the U.S. and The Joseph Hall Works would be able to buy the iron directly from Cowan.  This is how the Ontario Malleable Iron Co. came into being.  In 1872, the founding of OMIC was a great step forward made by Oshawa as an industrial community.  Along with OMIC, William was also one of the founding members of the business that would be known as Fittings Ltd.
     The Cowan brothers also came into the Ontario Loan and Savings, as well as Western Bank from the Gibbs after their fortunes collapsed. These were two prominent financial institutions and accomplished more for the growth of Oshawa, in its day, than any other factor.