"The Scarlet Band", a Sherlock Holmes pastiche set decades after Audubon's trip, focusing on a controversial religious movement called the House of Universal Devotion. Chronologically it is the last story set in this...
"Audubon in Atlantis", the first-published story in the series, set in 1843, focusing on John James Audubon's expedition to the continent/country of Atlantis. It takes place between The United States of Atlantis and Liberating...