It is easy to take our current rights for granted. We also like to think that the U.S. is on the forefront of human rights. However, a little history is always useful in giving us some perspective on just how recently equal treatment on different matters has been granted.
Wikipedia has a wonderful overview of women's suffrage and a table of the first date that women were allowed to participate (by voting) in elections by country. According to that table, in America, women were allowed to participate (by voting) in elections in 1920. Ironically, the U.S. was not the first country nor even close to being the first country to enable women's suffrage. Some of the countries that preceded us included Australia, Austria, Azerbaijan, Belarus, Belgium, Canada, Denmark, Georgia, Germany, Hungary, Ireland, Kyrgyzstan, Latvia, Lithuania, Luxembourg, Netherlands, Norway, Poland, Russia, Sweden, Ukraine, and UK.