I have taught a couple of classes on this topic making blocks from Eleanor Burns book: Underground Railroad Sampler; there is some controversy with this topic and no known hard facts to substansiate that quilts were used to navigate the underground railroad; however, there is evidence that the information was passed down verbally via stories; at any rate the underground RR is a part of our history and there is a possibility that some did use the quilts as part of the Underground RR; but whether you believe the stories, or not enjoy the process of making the blocks;