The date is May, 1923.
"When Richard Halliburton returns to the U.S. to nurture his fledgling writing career, he gets roped into investigating one of the biggest mysteries in American history—and gets more than he bargained for.
With German spies lurking, Halliburton must figure out a way to expose them and prevent them from collecting one of the biggest hidden treasures from the U.S. during the 19th Century … General Custer’s Gold."