The Importance of Culture in Fertility

In the 1700s, U.S. fertility rates were between six and eight kids per woman. In the 1960s before contraception, very few people were contraceptives. The difference from 6 to 8 to 2.5 was achieved without contraception or abortion on any grand scale. It's not random when technologies come into existence, right? Technology responds to demand; it's not an exogenous shock.