The best history on the subject comes from David Gordon, who has written a two piece history on the matter:
Part 1 is here.
Part 2 is here.
For a great glimpse into the intellect that Murray Rothbard was, be sure to listen to Lew Rockwell's interview of David Gordon, Memories of Rothbard.
UPDATE: I have recieved some emails regarding a Part 3 to David Gordon's history. He informs me:
I'm planning to do part 3, which will be an account of Murray Rothbard's remarks about Koch and Cato in Libertarian Forum.
UPDATE2: David Gordon's Part 3 on the Koch brothers is here.