James Donn (James Donn & Brother after 1873) was a prolific maker of shotguns of various types. I have 12 of them, including a 6 gauge percussion double and a massive sidelock breechloading single barreled 8 gauge. Donn opened his shop in 1859, having apprenticed to an earlier Canton, Illinois maker, James R. McQuaid. He started out as a maker of percussion rifles (I have four) but later re-apprenticed himself to an unnamed shotgun maker in Chicago. After his return to Canton, he made almost entirely shotguns, both percussion and breechloading. He took his brother William as a partner in 1873, and they continued the partnership until 1900. James Donn continued to work alone until 1911, although he could hardly compete with the prices of mass-produced shotguns. I have seen one hammerless double, which must have been among his last.
I suspect that Donn learned about making shotguns from Oliver P. Secor, who worked at various times in both Chicago and Peoria. In turn, Donn had an apprentice named Orlando B. Thorpe, who went on to make shotguns in Havana, Mason County, Illinois. I have an 8 gauge "live bird gun" and a 10 gauge double, made by Thorpe.