It's already the first International Women's day of the decade. The earliest "National Women's Day," was held on February 28, 1909, and it was organized by the Socialist Party of America, led by Theresa Serber Malkiel. To quote her:

It was not...a woman's fancy that drove them to it, but an eruption of a long-smolering volcano, an overflow of suffering, abuse and exhaustion.

This 'eruption' of 'volcano' for the rights of equality arose which inspired an International Socialist Women's Conference by the socialist leaders of the time in August 1910 with hundred women delegates representing 17 countries agreeing on convening the International Women's Day for equal rights and universal suffrage. However, the United Nations began celebrating IWD from 1975 - International Women's Year.

Post-2000, we have seen women being active in protests like never before like the Women's march or during the Arab spring or the contemporary world protests. IBTimes Singapore handpicked some bold quotes from the strongest women pre-2000's who fought for such rights:

I was taught that the way of progress was neither swift nor easy..I have frequently been questioned, especially by women, of how I could reconcile family life with a scientific career. Well, it has not been easy.
Marie Curie

Marie Curie
Marie Curie, chronomèter in hand, in the process of measuring radioactivity in the laboratory on Cuvier Street, 1904 nobelprize.org/© Association Curie Joliot-Curie

A Bird cannot fly with one wing only. Human space flight cannot develop any further without active participation of women... If women can be railroad workers in Russia, why can't they fly in space?
Valentina Tereshkova

Valentina Tereshkova
Valentina Tereshkova before her mission sciencemuseum.org.uk /Roscosmos

I do not wish women to have power over men; but over themselves.
Mary Shelly

Portrait of Mary Shelley
Portrait Mary Wollstonecraft Shelley by R Rothwell wikimedia commons/National Portrait Gallery

For us there is no more a 'women's question' from the [ruling class'] standpoint than there is a men's question...We are not women arrayed in struggle against men but workers who are in struggle against the exploiters.
Elanor Marx

Eleanor Marx Aveling
Eleanor Marx Aveling, daughter of Karl Marx wikimedia commons

If one proves the equality of two numbers a and b by showing first that a ≦ b and then that a ≧ b, it is unfair; one should instead show that they are really equal by disclosing the inner ground for their equality.
Emmy Noether

Portrait of Emmy Noether
Portrait of Emmy Noether wikimedia commons

Women should be respected as well! Generally speaking, men are held in great esteem in all parts of the world, so why shouldn't women have their share? Soldiers and war heroes are honored and commemorated, explorers are granted immortal fame, martyrs are revered, but how many people look upon women too as soldiers?...Women, who struggle and suffer pain to ensure the continuation of the human race, make much tougher and more courageous soldiers than all those big-mouthed freedom-fighting heroes put together!
Anne Frank

Anne Frank laughing at the school
Anne Frank laughing at the school wikimedia commons/annefrank.org

Women's freedom is the sign of social freedom.
Rosa Luxemburg

Rosa Luxemburg colorized photo
Rosa Luxemburg colorized photo. wikimedia commons/Emijrp

Look at what Mary Winsor says in this photo of her holding a banner

Mary Winsor (Pennsylvania), holding suffrage prisoners banner
Mary Winsor, holding suffrage prisoners banner in Pennsylvania, 1917 wikimedia commons/Harris & Ewing

I would earnestly ask my sisters to keep clear of both the jargons now current everywhere (for they are equally jargons); of the jargon, namely, about the "rights" of women, which urges women to do all that men do, including the medical and other professions, merely because men do it, and without regard to whether this is the best that women can do; and of the jargon which urges women to do nothing that men do, merely because they are women, and should be "recalled to a sense of their duty as women," and because "this is women's work," and "that is men's," and "these are things which women should not do," which is all assertion and nothing more. Surely woman should bring the best she has, whatever that is, to the work of God's world, without attending to either of these cries.
Florence Nightingale

Crimean War: Florence Nightingale with her lamp at a patient's bedside.
Crimean War: Florence Nightingale with her lamp at a patient's bedside (Painting by Henrietta Rae) wikimedia commons/Wellcome Images