Looking back over the past 100 years, it becomes clear that women have not wasted a moment. Here's a quick look at some of the things women have accomplished in the 20th century:

1912 Juliette Gordon Low founds the first American group of Girl Guides, which will eventually be renamed the Girl Scouts of the U.S.A.

1917 Jeannette Rankin of Montana becomes the first woman elected to the U.S. Congress

1920 On August 26, the 19th Amendment to the Constitution is ratified, guaranteeing women the right to vote

1921 Margaret Sanger organizes the American Birth Control League, which evolves into the Federation of Planned Parenthood

1932 Amelia Earhart became the first women to fly solo across the Atlantic Ocean

1933 Frances Perkins, the first woman in a presidential cabinet, serves as Secretary of Labor during the entire Roosevelt administration

1937 Professor Jean Broadhurst identifies the measles virus

1946 Six women are given the task of calculating trajectories of WWII missiles, thus becoming the first computer programmers

1955 Rosa Parks refuses to give up her bus seat to a white passenger, thereby triggering the Montgomery bus boycott and giving impetus to the Civil Rights Movement

1959 Jerrie Cobb is the first woman to undergo the testing developed for the selection of the Mercury Astronauts

1962 Rachel Carson writes The Silent Spring, laying the groundwork for the environmental movement

1963 Betty Friedan publishes The Feminine Mystique, laying the groundwork for the modern feminist movement

1969 The Boston Women's Health Collective publishes Our Bodies, Ourselves: A Book by and for Women

1972 Barbara Jordan becomes first African-American woman elected to Congress from a Southern state

1973 Billie Jean King beats Bobby Riggs in "The Battle of the Sexes"

1973 In Roe v. Wade, the Supreme Court establishes a woman's right to abortion

1981 Sandra Day O'Connor is the first woman appointed to the U.S. Supreme Court

1983 Sally Ride is the first American woman in space

1985 Libby Riddles is the first woman to win Alaska's Iditerod sled dog race

1999 The U.S. Women's Soccer team wins the World Cup