Death of All Life on Earth Iv : Humans Did Survive the War on Co2, Could They Survive the War on Each Other?

Since the Period of Death, survivors wondered if any of the government of the old USA survived. Then, a small group actually traveled to the eastern seaboard and Washington DC to find out. They found that most of the survivors there were hostile and had to fight nearly every step of the way. This final book of the series finishes the story of death for most and survival of a few.