We study the impact of marital property legislation passed in the US South in the 1840s on households’ investment in risky, entrepreneurial projects. These laws protected the assets of newly married women from creditors in a world of virtually unlimited liability. We compare couples married after the passage of a marital property law with couples from the same state who were married before. Consistent with a simple model of household borrowing that trades off agency costs against risk sharing, the effect on investment was heterogeneous. It increased if most household property came from the husband and decreased if most came from the wife.