I picked up the audio of this for a road trip and loved it. Vowell (who wrote Assassination Vacation, which I plan to read next), tells the story of the founding of Boston and the Massachusetts Bay Colony by the Puritans. These were not the Mayflower-ers of 1620 who Vowell explains wanted full separation from the Church of England; rather, this group sailed on the Arbella in 1630 and wished to remain (tenuously) connected to the C of E, but free to practice in their own style.
The stories of a few key individuals are highlighted here: Governor John Winthrop, Rhode Island-founder Roger Williams, and fellow Massachusetts banishee Anne Hutchinson. Vowell looks closely at journals, letters and sermons to trace the specifics of their Puritan, Calvinistic thought and the enormous impact their words and deeds have today on American Culture and foreign policy. Vowell is a radio veteran, and the audio quality reflects this, with voice appearances by Catherine Keener, Eric Bogosian and others and gorgeous musical accompaniment.