Because federally funded family planning programs served mostly lower income women and operated in only one-fifth of all US counties in 1974, the program accounts for a modest portion of the large decline in the general fertility rate from 1959 to 1974. Nevertheless, these programs had a substantial effect on the women they served. This paper’s estimates imply that federal family planning dollars reduced childbearing among poor women by 19 to 30 percent within 10 years—magnitudes large enough to account for half to three-quarters of the 1965 gap in childbearing between poor and nonpoor women. Future work should consider how family planning programs affected a host of longer term outcomes including the age structure of poverty, children’s resources and life chances, and economic growth.