Percentage of babies born to unmarried women in the United States. In 2023, 40.0% of all births in the United States were to unmarried women, accounting for 1,440,031 births out of roughly 3.6 million total births. While this was a slight increase from 39.8% in 2022, it remained below the record high of 41.0% reached in 2009. The birth rate among unmarried women also continued its long-term decline, falling to 36.4 births per 1,000 unmarried women aged 15–44, reflecting both lower overall fertility and evolving family structures. Births outside of marriage were once relatively rare in the United States. In 1940, only about 4% of births were to unmarried women. The share rose rapidly during the 1960s and 1970s as marriage rates declined, cohabitation became more common, and social attitudes toward having children outside marriage shifted. By 1980, the figure had climbed to around 18%, reached roughly 33% by 2000, and peaked at 41% in 2009 before stabilizing at about 40% over the past decade. Importantly, this does not mean that 40% of children are being raised by a single parent. A substantial number of unmarried mothers are in long-term cohabiting relationships, meaning many children born outside of marriage are still growing up in two-parent households.(Historic Vids)