I Desperately need help with this. PLEASE HELP!!?

I am doing a projest about three Americans who have changed history. The only problem is that they have to be lesser-know people. So it cant be people like harriet tubman or anybody that you really have heard of. Here is what it says to do. Choose 3 American citizens throughout history that have had an impact on how we live today.Focus on there backgroud, life experiences, and what the did to make us remember them. Rather than focus on individuals that are commonly ociated with holidays or events probe a little deeper and pick some people that are lesser-known, but important nevereless. PLEASE HELP I CAN NOT FIND ANYBODY!!!