The people who worked for the underground railroad risked life and livelihood to help slaves escape to the North. But how did runaway slaves know how to find people on the underground railroad? There emerged a system of codes, which people in the know could use to secretly transmit information about escape. Songs were one method. According to a recent book, quilts were another, less well known, method.

According to the recent book Hidden in Plain View, by Raymond Dobard and Jacqueline Tobin and based on the oral testimony of Ozella McDaniel Williams of South Carolina (who died before the book was published), quilts of a certain pattern would be displayed, ostensibly for airing, drying or decoration, but would have a hidden meaning. Patterns, combinations of patterns, the way the quilt was displayed, and the colors used could all send a message. All of the patterns named here are traditional quilt patterns. According to Williams:

Tumbling Blocks was the sign that people were going to run. The quilt would be folded in such a way as to display a certain number of blocks. The number of blocks displayed indicated the number of days until the escape.

The Wagon Wheel pattern could mean "We're leaving today," or else, "Transportation available here."

The Crossroads pattern is four blocks in an "X". It indicated a major city or junction on the underground railroad (the biggest of which was Cleveland, Ohio). Other directional quilts would be placed to point the way to the next crossroads.

The flying geese is a quilt pattern of triangles. Some triangles are a different color than the rest. The direction these differently colored triangles pointed in indicated the path to the next crossroads.

The Log Cabin pattern would be hung outside safehouses which were willing to provide shelter to runaways.

The Bow Ties pattern indicated a place where new clothes could be obtained.

Williams claimed that this quilt code had been passed down through her family for generations as a secret oral tradition. Since the publication of Hidden in Plain View in 1999, however, many historians have questioned whether the quilt code actually existed, since the book was entirely based on the testimony of a single woman, and so far no other documentary evidence has emerged to corroborate Williams' story.