This article provides insights into the long-term trends of intergenerational mobility of men and women born in the United States. We study both absolute and relative social mobility and analyze in some detail the relation between education and intergenerational mobility. We document massive changes in the occupational structure and the educational system of the US. Especially women benefitted consistently from the trend towards a post-industrial society, experiencing decreasing levels of downward mobility, while tendencies towards polarization of the occupational structure increased downward mobility for men. We find little evidence that education is becoming increasingly a motor for absolute upward mobility but our findings suggest that class placement is becoming more heterogeneous across educational levels. Our assessment of changes in relative mobility levels and how they relate to changes in education reveals quite different stories for men and women. While class fluidity increased among men, it remained stable among women. We find that the moderate increases in class fluidity among men are primarily driven by educational expansion and the compositional effect. For women, on the contrary, educational expansion alone had the potential to decrease female fluidity - chiefly since it elevated women's qualifications and enabled them henceforth to gain access to occupations restricted to their fathers.