We show that separation has been a relevant outcome of American relationships over the last century and that separated women have worse economic outcomes than those divorced. A transferable-utility model of marriage, separation and divorce indicates that the welfare effects of divorce legislation depend on considering separation as an alternative. Empirically, the adoption of unilateral divorce laws reduced separation and increased divorce, particularly among low-educated women. A calibrated model indicates heterogeneous welfare effects of unilateral divorce with gains being concentrated among women with lower education. Desertion laws with very short duration generate similar gains for women.