Actor Allusion: What is it with Lennie James and series which deal with post-apocalyptia? Here's it's nukes. Next time we see him, it's zombies.
Shout-Out: A sick version to the novel it's based on, Alas, Babylon. In that book, Denver ended up being the capital of (what's left of) the United States. In this series, Denver's the first to go.
What Could Have Been - The original plan for the series was that the first part of the story would've focused Jericho, Kansas. Then the story would've shifted to Cheyenne, Wyoming for the second part. Finally that last part of the story would taken place in New York City. If the series would've lasted long enough, it would've dealt with the Second American Civil War.