We use data from two national surveys of married individuals—one from 1980 and the other from 2000—to understand how three dimensions of marital quality changed during this period. Marital happiness and divorce proneness changed little between 1980 and 2000, but marital interaction declined significantly. A decomposition analysis suggested that offsetting trends affected marital quality. Increases in marital heterogamy, premarital cohabitation, wives' extended hours of employment, and wives' job demands were associated with declines in multiple dimensions of marital quality. In contrast, increases in economic resources, decision-making equality, nontraditional attitudes toward gender, and support for the norm of lifelong marriage were associated with improvements in multiple dimensions of marital quality. Increases in husbands' share of housework appeared to depress marital quality among husbands but to improve marital quality among wives.