![](https://www.historynet.com/wp-content/uploads/2019/09/ACWP-191100-MERRILL-03.jpg)
As shown on this map of Franklin, Tenn., Merrill and his team used ruled paper with 1-inch squares for their fine-tuned creations. (William Emery Merrill/Library of Congress)
As shown on this map of Franklin, Tenn., Merrill and his team used ruled paper with 1-inch squares for their fine-tuned creations. (William Emery Merrill/Library of Congress)