Around 1870 , Deering left that business .
Around 1870 , Deering partnered with Elijah Gammon , providing $40,000 in funding for the production of a horse - drawn grain harvester developed by brothers William and Charles Marsh .
Around 1870 , Deering left that business and partnered with Elijah Gammon , providing $40,000 in funding for the production of a horse - drawn grain harvester developed by brothers William and Charles Marsh .