International Women's Day

As some or most of you know, March 8 is International Women's Day. This year is the first time that I am actually paying attention to it. This has to do with my job. I work for a women's organization which, of course, celebrates that day. But even more interesting is the question, what do all the other people know about this??? When did IWD start and why? And how is it celebrated in all those different countries?
So, all of my friends, who are reading my blog, please, send me an e-mail regarding these questions. Thank you so much!!!