There is some specutlation that the story of the underground railroad quilts is exactly that - a story - unfortunately. Maniy quilt historians say that eome of the blocks which were meant to have significance in the quilts - such as the log cabin- orginated at a date later than the Civil War and therefore could not have been used in these quilts. Barbara Brackman has a good book out debunking this story. Eleanor Burns has a book out with the patterns and what each block means.