Book 2 of the Wakeful Wanderer's series.
Book 1 is The Wakeful Wanderer's Guide to New New England & Beyond. That's a good place to start. It's available here.
The America of our near-future is divided across socio-economic and technological-philosophical lines. The Traditionalists eschew any and all post-human technologies in favor of tangible materials. They uphold strict hierarchical structures based on religion, family, and leadership. They long for the return of the global markets wiped out by a world-shaking disaster called The Great Tide. The Interconnected stand in stark opposition to their ways, living without property, family, or religion, and modifying their bodies with the help of new and invasive technologies. They speak to each other wordlessly, employing a technological telepathy they call 'thexting' to communicate mind to mind, and embrace the gifting economy of Merit to maintain their post-scarcity lifestyles.
Marto, the traveling Interconnected historian, has exiled himself to protect the ones he loves from his dark secret. In his absence, Helen, a runaway Traditionalist aristocrat, struggles to find her place among the Interconnected, unwilling to return to her cruel family. Reyleena, the former head of security in the Interconnected town of Reverside, has returned to a life of quiet solitude, broken occasionally by the impositions of The Other, an omnipresent AI, who will not leave her alone. Meanwhile, Barnabas, the Traditionalist leader of New Atlantic, fights to return to his township in the wake of an attack. Nora, his sister, remains in Reverside and must come to terms with her new life in captivity.
BOOK 2
After chaos destroyed, America fell into pandemonium and there was no communication with the U.S. After a pandemic crisis on the East coast, most civilization was abandoned near the Atlantic Ocean. After that, the world slowly began to fall to pieces and almost every country made a scramble to figure a way to make space travel easier so they could colonize a planet. But a new leader came out of the ashes and proclaimed they would consider the apocalypse a "rebirth" and proceeded (with his advanced engineering) to clear radioactivity from America and make it livable again.
With the help of his crew, he builds a high security city and begins to build out past the east coast. Shortly after he rebuilds NY, he disappears and his advisor rises to power. He is a fair but cruel master (calling himself a Lord) and some people refuse to work for him. These people manage to escape the oppression of the Lord and live out on the wasteland that was once a great country. Some band together to make right communities and others rough it out by themselves, scavenging for a living.