http://history.house.gov/ . One of the tabs - is education here you will find lesson plans. There are biographical sketches about members.
Have you ever heard of Senator Hiram Revels a Republican from Mississippi? I had never heard of him. After reading about him. I asked myself why don't we feature information like this in our text books?
Hiram Revels of Mississippi and Joseph Rainey of South Carolina arrived on capital hill in 1870. They held seats that a decade earlier were held by slave owners. Senator Revels was the first African American senator to be elected, prior to Mississippi being re-admitted to the United States. http://history.house.gov/Exhibitions-and-Publications/BAIC/Black-Americans-in-Congress/
There are lots of areas to explore.