As in all topics in history we need to be aware of the difference between myth and fact. Although myths are also a part of our culture history students need to be clear on what has been proven to be true and what is based on stories that may not be accurate. Oral history can be a great starting point for research but stories alone do not establish fact. Follow this link to Fact vs. Fiction in Quilting History for information that will help make sure your papers and lesson plans are are clear about what is historical fact and what is theory.
Occasionally I get an email from a student whose teacher has given an assignment regarding Colonial Quilts. Usually the teacher has just assumed that quilting was common in America's colonial days. This has been a common myth since early in the 20th century. The article, "Colonial Women ~ Quilters or Not?", gives the truth about colonial quilting.
I especially need to mention my concerns about teaching the story that specific quilts were used in the Underground Railroad. If you do decide to use a lesson plan along these lines be certain the children understand it might be one of several myths about the Underground Railroad. It's not that there is proof quilts were never used in the Underground Railroad but that the information about maps and patterns that is popular today is unsubstantiated. It's quite possible that quilts were never used as signals but they were certainly used for comfort to the fleeing slaves.
If you are doing a unit on the Underground Railroad explain to the children that we don't know exactly what kinds of signals and maps were used but the important thing is that enslaved people had the courage and the determination to be free. They had to use wisdom and secrecy in their plans to escape. Perhaps having children devise their own secret signals and maps would a better way show them how these African Americans found ways to use methods that were "hidden in plain view".
More Information:If your goal is to teach a unit for Black History Month There are other quilt related topics as well. Consider teaching about Harriet Powers' story quilts. Go to Harriet Powers: A Freed Slave Tells Stories Through Quilting to learn more about this former slave woman and her quilts. Less closely related to quilting is the story of Elizabeth Hobbs Keckly: From Slave to Dressmaker for Mary Todd Lincoln.