The Old South's economic stake in western land expansion and slave migration is examined in a two-region, general equilibrium model of slave mobility. The model separates the effect on the Old South's assets and slave population of more western land from that of slave sales per se. The authors conclude that the Old South had no economic stake in the New South. The most conservative estimate reveals that a doubling of western lands in 1850 would have increased Old South wealth by less than two percent.