Thesis

I need help writing a thesis for history. It has to answer te question: How Freedom changed over the course of United States History for a specific group of people... we have to use a group of people, I chose African Americans, and three events (or groups) to represent it, in which i chose quackers, american anti slavery society, and hippies. So far i've got "From 1600 until 1900’s in the United States, different groups of individuals fought for the Freedoms of African American’s while enduring hardships of their own, in the end accomplishing to"