The Seventies
Most textbooks couldn't do as a good a job placing the seventies in context as this article. Teachers would be well served reading this before planning.
The iconic photograph is one of the most requested items at the national archives and is the subject of a comple documentary film. This is a relatively brief but important exercise in historical thinking. Students look through four pieces of evidence (primary documents) to determine the credibility of each piece of evidence and how the evidence fits together. Finally, they come up with a plausible explanation of why the photograph was taken and how you came to that particular conclusion.
This is a lesson that has students "doing history", they not only have to come to a conclusion based on primary source evidence, they have to explain how they came to their conclusions.