PBS has many great stories and lesson plans for teaching about American history. The pest one that I have found and utilized was their segment on WWI. The Great War gives a very in depth look at the build-up, conflict, and the aftermath of the first world war. It helps to paint a detailed picture of the past in a way that makes the second world war as well as many curent conflict make sense. I was able to teach this lesson this winter when tensions in Israel were on the rise and conflict was turning bloodier by the minute. This was a very good tool for the kids to understand the conflict surrounding the holy land.
The state of Alaska offers a very good website that is designed for home schooled students as well as a credit recovery program for the Alaska History standard for the state. This website has been a very valuable resource for me to brush up on Alaskan issues in a timeline manner that includes: Native History, the Russian period, American Territorial period, and Statehood. There isn't much for lesson plans here, but it is packed full of good information that you can use in conjunction with the Alaska Flipchart lesson plans in my IEP that can be used to teach an entire semester of Alaskan History.