It exists. Or persists.
The magazine that gave us the Civil War historiography of today has an up-to-date web presence, with new articles even. American Heritage.
And they have a little feature allowing me to sign up for notification whenever a new article about George B. McClellan is put up.
The standard of contributors is not what it was during the Centennial, however: "Alexander Burns, an undergraduate at Harvard College, is a frequent contributor to AmericanHeritage.com." Not that an undergrad with historic sensibility couldn't do better than the old crew trying to write its way through complex problems.
But do I wonder if any contributor has permission to buck 50 years of editorial policy.