National Women’s History Month dates back to March 8, 1857, when women from New York City factories staged a protest over working conditions.

International Women’s Day was first observed in 1909, but it wasn’t until 1981 Congress established National Women’s History Week to be commemorated the second week of March. In 1987, Congress expanded the week to a month. Every year since, Congress has passed a resolution for Women’s History Month, and the President has issued a proclamation.

The U.S. Census reports there are 157.2 million females in the United States as of Oct. 1, 2010, compared to 153.2 million males.

At 85 and older, there were more than twice as many women as men.

The median annual earnings of women 15 or older who worked year-round, full time, in 2009, up 1.9 percent from $35,609 in 2008 (after adjusting for inflation) to $36,278. Women earned 77 cents for every $1 earned by men, according to 2009 stats provided by the Census.

More women 25 and older in 2009 had a bachelor’s degree (29.9 million) compared to men (28.7 million).

Receipts for women-owned businesses in 2007 totaled $1.2 trillion. There were 141,893 women-owned businesses with receipts of $1 million or more.

More than 45 percent of women-owned businesses operated in health care and social assistance, and other services, such as personal services; professional, scientific, and technical services; and repair and maintenance. Women owned 52 percent of all businesses operating in the health care and social assistance sector. Wholesale and retail trade accounted for 36 percent of women-owned business revenue.

California in 2007 had the most women-owned businesses at 1 million. Texas was second with 610,162.