This article examines the long‐term impact of legalized abortion on childbearing by unwed teenagers in the United States. I find that the 1970 legalization of abortion in the repeal states led to about a 6% reduction in unwed childbearing rates for white women aged 15–20 who were born in these states immediately after abortion became legal. I find a larger long‐term impact for African‐American women of the same ages: a 7.5%–13% reduction in unwed childbearing. My estimates are smaller and not as precise for the effect of Roe v. Wade. This outcome is not surprising given that I am able to estimate only a potential lower bound of the effect on unwed childbearing rates. On the other hand, when I estimated a Difference‐in‐Difference regression for the non‐repeal states assuming that there was no national trend that affected the childbearing behavior of the treatment age groups and their respective control age groups separately, I found that the true effect of Roe v. Wade on childbearing by unwed teenagers was about an 11% and 3% reductions for white and African‐American teenagers, respectively. (JEL J13, I18)