Peggy Bendroth's new book The Last Puritans: Mainline Protestants and the Power of the Past is not a story about Thanksgiving. But the declaration of Thanksgiving as a national holiday, one of Abraham Lincoln's last acts as president, came at a striking moment for Congregationalists. Like the rest of the country they were struggling with some big existential questions as the Civil War wound to its conclusion. In their case the problem was history, and whether their storied New England past would be a help or a hindrance as they contemplated their future.