Who organized the very first women's day?

The very first International Women's Day was organized by the Socialist Party of America in 1909. It was held on February 28, in New York City, to honor the 1908 garment workers' strike and to advocate for women's rights. The idea gained international traction, leading to the first official celebration in 1911 in several European countries. The day has since evolved into a global event to promote women's rights and gender equality.