Invented the mechanical mower-reaper in the 1830's. Was to western farmers what the cotton gin was to southern planters. One person could now do the work of five. Helped western famers who wanted more land to make more profit. Because of this invention humble plowmen became capitalists investing in land. Changed the west from subsistence farming to production for the market – cash-crop agriculture came to dominate the west. Increased amount of land led to transportation revolution.