In 1960, 5 percent of all pregnancies occured to unmarried mothers. By 1999, percentage rose to 33. One in every three children born in America is born to unwed mother. In 1970 it was 10.7 percent and 1980, 18.4 percent and 1990, it was 28 percent. Latest CDC stat on birth to unmarried women stands at 36.9 percent, ie 1,527,034.
Contrary to conventional notion that most illegitimate children are not being born to teen mothers. Over the past four decades age of unmarried mother giving birth has risen from teen girls to twenties and now in thirties. Also it moved beyond black poor girls to well-to-do white and other migrant groups. See detailed stat by race from 1970 thro 2004 on unmarried childbirths in US.
Birth control revolution that was supposed to prevent unwanted pregnancies and allow peopple freely engage in sex without any fear. Inceasingly sex-driven popular culture and anti-marriage sentiment prevalent in America today has taken any stigma out of free format sexual activity. Growing promiscuity, Cohabitation etc are only making this problem worse. But all of it is not without any consequence as many would like to believe.
The term illegitimate children are no more in use and is considered oppressive. Out of wedlock childbirth is the more trendy usage these days. No matter how well we sugarcoat such bitter social experimentation or legislate new policies by the government, this moral crisis cannot be easily resolved. Personal sexual ethics have a larger social, cultural and political consequences. Unless we address the core moral crisis in America, nothing else we do will matter much!