Why Some Women Are Wearing White to President Donald Trump's Address

President Donald Trump is giving his first joint address to the nation on Tuesday, and women in the House Democratic Caucus did something special to show solidarity with other women: they wore white, the official color of the women's suffrage movement.

Rep. Louis Frankel (D-Fla.) tweeted that congresswomen wore white to "oppose Republican attempts to roll back women's progress."

Anti-abortion rhetoric was at the center of Trump's campaign, and he took a hard line against Planned Parenthood because 3 percent of their health services are abortion services (none of which is paid for with federal dollars). On January 23, Trump reinstated the "global gag rule" also known as the "Mexico City Policy," which stripped non-governmental organizations around the world of aid, if they offered or even mentioned abortion in their published materials.

The first female Democratic presidential nominee Hillary Clinton wore white during the presidential debates and also to Trump's inauguration in January, according to The Hill. Democrat Geraldine Ferraro, the first female vice-presidential candidate for a major party also wore white when she gave her acceptance speech in 1984. Shirley Chisholm, also a Democrat, wore white when she became the first black woman to be elected to Congress in 1969.

How did white become a color for women's rights?

In 1908, British suffragette Emmeline Pankhurst of the Women's Social and Political Union picked three colors for women to wear at a Hyde Park protest in London. She picked white for purity, purple for dignity and green for hope, but white became the predominant color for women's movements in the United States.

RELATED: Women Are Taking on a Major Issue in American Politics Ever Since the Election