b. November 7, 1808, in Monongahela, Pennsylvania; d. March 1, 1865, in Springfield, Illinois. On May 30, 1833, Irwin married Clara C. Doyle in St. Louis, Missouri. Irwin was involved in mercantile trade with John Carr and Augustus Carr. Irwin dissolved the firm early in 1834. He then moved to Springfield, Illinois, where he formed a partnership with John Williams, one of the pioneer merchants of the city, in the dry goods trade. Subsequently, Irwin was also connected with his brother, John Irwin , in the mercantile business. In 1850, Irwin was a merchant and owned real estate worth $16,000, and in 1860 he was a banker with real estate worth $35,000 and personal property worth $40,000. Robert Irwin also served as the secretary for the Marine and Fire Insurance Company.