In a sweeping synthesis of American history, Mary Ryan demonstrates how the meaning of male and female has evolved, changed, and varied over a span of 500 years and across major social and ethnic boundaries. She traces how, at select moments in history, perceptions of sex difference were translated into complex and mutable patterns for differentiating women and men. How those distinctions were drawn and redrawn affected the course of American history more generally. Ryan recounts the construction of a modern gender regime that sharply divided male from female and created modes of exclusion and inequity. The divide between male and female blurred in the twentieth century, as women entered the public domain, massed in the labor force, and revolutionized private life. This transformation in gender history serves as a backdrop for seven chronological chapters, each of which presents a different problem in American history as a quandary of sex. Ryan's bold analysis raises the possibility that perhaps, if understood in their variety and mutability, the differences of sex might lose the sting of inequality.