I thought it was an attempt of his to
This book is one of the most engaging history books I've read about the founding.
It shows our founders' flaws as well as their glories.
It tells the tale behind some turning points that I thought I knew (from those authors whose perspectives I agreed with) and shows the conflicts among the parties involved in the founding with good detail, pros and cons.
I'm reading now about the Danbury Baptists and the letter to them from Jefferson about a "wall of separation".
I thought I knew this story, but Anderson portrays it more deeply including referencing earlier drafts and a background on Jefferson's position (that could me mis-construed to represent an ACLU position).
While Jefferson was opposed to National Days of Thanksgiving or Prayer, etc. as a principle, he was not opposed to the bedrock of morality (God's Law, or the "Law of Nature's God") forming our legal code.
What I came to realize out of this is that, while we have an explicit Constitution whose rationale is explained in the Federalist and Anti-Federalist Papers, jointly authored documents reflecting a consensus of founder's opinion
which liberal legal scholars choose to ignore as passe,
a letter to a group of formerly persecuted Christians promising them religious freedom, is held up as a Constitutional Precept, being only the opinion of Jefferson and not a legal document.
And so, the God whose Scripture informed the rationale of the Revolution in many ways, is now cast out of the government altogether.
If we are to ignore the Constitutional precepts as they were originally formed, what do we care about what Jefferson wrote to the Danbury Baptists?