Harriet tubman, she didn't want the slaves to continue being slaves so she invented the underground railroad.
the japanese version of robin hood (goemon), he stole from the rich and give to the needy
Marie curie - she discovered radioactivity
copornicus - did some mathematical equations and pondered about science
renaissance painter - showed perspective in drawings
and lots others
We wouldn't know more about philosophy without copornicus.
http://listverse.com/2013/03/22/top-10-most-famous-people/