U.S. fertility rate was dropping long before the 60s (and even before the great depression) [1] though it does sound like contraception may have had an impact.

U.S. fertility rate was dropping long before the 60s (and even before the great depression) [1] though it does sound like contraception may have had an impact. [2] [1] https://www.prb.org/resources/the-decline-in-u-s-fertility https://www.prb.org/resources/the-decline-in-u-s-fertility [2] https://www.cdc.gov/mmwr/preview/mmwrhtml/mm4847a1.htm https://www.cdc.gov/mmwr/preview/mmwrhtml/mm4847a1.htm