A project that was done with some students in our building this year was based on Dear America. The opportunity was offered to students who enjoy writing, and to students who enjoyed drawing. It basically worked like this:
Students read/examined Dear America books
They then chose a time period of interest to them and researched what life was like in our state during that time period
Students wrote their own Dear America story, then worked with one of the illustrators to discuss the story.
Illustrators took over and created illustrations for the book.
In order to work on the project, students involved in the research/writing met for 45 minutes in the LMC (with librarian and an instructional resource teacher) 3 days per week. They were allowed to miss class without being asked to make up the work. They were also allowed some time to read for their project within the reading block.
Overall the experience was very good for students. If I recall correctly, the writing part of the project took place over the course of about six weeks.