The percent of non-marital births in the United States has steadily increased over the past few decades, from an estimated 4.5% in 1955 to 35.6% in 2004. Several factors account for such trends. Over the past decades, an increasing proportion of women has postponed marriage, while increased numbers of unmarried couples cohabit. The rates of non-marital births have increased, while rates of marital births have decreased, contributing to an increased percent of non-marital births. This fact sheet illustrates the recent trends in non-marital birth rates. (Author abstract)