The series is set within an alternate history of the 1930s invented by Weisman and McCoy. Within this divergent timeline, the United States has collapsed, and air travel has become the most popular mode of transportation in North America; as a result, air pirates thrive in the world of Crimson Skies. In describing the concept of Crimson Skies, Jordan Weisman stated he wanted to "take the idea of 16th century Caribbean piracy and translate into a 1930s American setting."
