This paper uses new methods to determine the sources of the sharp fall and then the steep rise in personal income inequality between 1959 and 1989. The increase in the proportion of single-head families tended to boost inequality over the entire period. Forty percent of the reduction in income inequality in the 1960s occurred because of the decline in earnings inequality among male heads of families; more than one-third of the increase in inequality after 1969 occurred because inequality in male earnings soared. Since 1979 females' gains in earnings have increased inequality because these gains have been concentrated increasingly in families with high incomes.