When Thomas James Dunn enlisted in the U.S. Army during the Mexican War, he scarcely could have imagined the adventures that lay in store. He kept a journal, detailing a story of exploration, faith, discovery, gold, and encounters with Native American tribes -- friendly and otherwise! Along the way, he made history, blazing trails and helping to secure the Southwest for the United States. This journal is published with annotations and dozens of pictures, describing and illustrating the people and places Cpl. Dunn encountered during the longest infantry march in American history.