History of Lisp macros

[Alan Bawden <ALAN at MIT-MC>]

Can anyone tell me anything about the history of Lisp macros?  I seem
to remember that the idea was introduced during the early seventies
into MacLisp.  I thought that there was an MIT-AI memo or some such
document that actually contained the original proposal, but I can't
seem to find anything like that.

Anybody know the real story?  Do macros go back further than this?
Was MacLisp really the first Lisp to have them?  Thanks in advance.

				-Alan