You don't need a mask or cloak to be a hero, and you don't need superpowers, either- just courage, determination, and hard work. Throughout history, there have been many so-called "ordinary" people who used their talents to make our world a better place. Here are 20 such men and women, from suffragettes and scientists to aviators, artists, and activists. Some had to overcome great challenges, and others had to try and try again, but all ultimately succeeded in their revolutionary achievements. Best of all, you can be a superhero, too--with or without your cape!