The "Quilt Code" and Underground Railroad

This is not strictly thimble-related, though it is sewing-related.
February is Black History Month and I have gotten many requests for books on the connection between quilts and the Underground Railroad: that various quilt patterns were used to help escaped slaves navigate the underground railroad. The most requests are from teachers for children to read. I even got a request for a coloring book of quilt patterns for kids to color, to, in effect, make their own Freedom Quilts. This would be a great activity to help kids learn about and remember the Underground Railroad. Unfortunately, the whole Quilt/UGRR connection is not a historical fact.
There are several websites dedicated to revealing the truth. One that is particularly informative and has links to many other sites is Leigh Hellner's Betsy Ross redux: the Underground Railroad "Quilt Code." Another is Kimberly Wulfert's UGRR page at antiquequiltdating.com. I am not, in the words of one of the authors of a bestselling Quilt Code book, an "angry white quilter." My forebears include both quilters and abolitionists; one branch owned one of the "stations" along the UGRR. I don't have an axe to grind. I just believe that the truth is better than a lie. Particularly a very lucrative lie. The courage of those who escaped the chains of slavery does not need this sort of embroidery to embellish it.