Drafting Constitutions and Federalism
I've been reading David McCullough's fascinating recent biography of John Adams. There is much in it about states' rights v. federalism, and about the debates on point during the drafting of the Constitution. Those debates ultimately defined the United States and have guided our federal v. state jurisprudence ever since.
The Europeans are currently drafting their own constitution for the EU, and they seem to be struggling over many of the exact same issues the Americans struggled with more than two centuries ago. Fascinating, if you ask me. Read about it here.