In this speech, Lincoln discusses agricultural technology and argues for the moral superiority of the Northern free labor economy over Southern chattel slavery. Lincoln gave the speech at a fair put on by the Wisconsin Agriculture Society to display advances in tools and methods of agriculture. Lincoln suggests that technological advances liberate men from the dehumanizing effects of certain labor practices. Lincoln also addresses the increasingly prominent “mudsill” theory advanced by defenders of Southern slavery like James Henry Hammond. According to this theory, all societies necessarily involve some form of slavery, and the North was engaged in the de facto slavery of the working class. In this view, Northern critiques of Southern chattel slavery were hypocritical. Lincoln contended that the opportunities for social mobility made the Northern economy crucially different—and morally superior—to the Southern slave system.