Question

~The history of the U.S. can be seen as a struggle- not always successful- for rights. How can this theme be seen from the time of the American Revolution to the present?~
Does anyone have ideas about what I could write about besides stuff like the Civil Rights movement, campaign for women's rights, Japanese camps during WWII, and suffrage of women and other minorities, etc.?

you might look at the development of the "rights of the accused". An example would be the inclusion of the Miranda Law. There is other legislation which has clarified the 5th Amendment.