The New York Times's obituary of the historian Forrest McDonald. Does any work of constitutional history have a more engaging introduction than his Novus Ordo Seclorum: The Intellectual Origins of the Constitution (1985)? Also: Seth Tillman's and Al Brophy's appreciations.
Update: More appreciations: R. B. Bernstein in H-Law; Richard Brookhiser in the National Review (h/t Seth Hillman), and on the website of the University Press of Kansas, McDonald's former editor Fred Woodward. And here's an appreciation in the Tuscaloosa News.