Trovi qualcosa dello stesso Lamport
http://research.microsoft.com/users/lamport/pubs/pubs.html#latex
In the early 80s… I was a TeX user, so I would need a set of macros. I thought that, with a little extra effort, I could make my macros usable by others. Don Knuth had begun issuing early releases of the current version of TeX, and I figured I could write what would become its standard macro package. That was the beginning of LaTeX. I was planning to write a user manual, but it never occurred to me that anyone would actually pay money for it. In 1983, Peter Gordon, an Addison-Wesley editor, and his colleagues visited me at SRI.
Da quello che scrive Lamport, ho seri dubbi che si possa parlare di un anno esatto in cui il Nostro comincia a scrivere LaTeX. Visto che Lamport ha preso parte allo sviluppo di TeX, può darsi che le prime “macro” risalgano addirittura a prima del 1982.
Sono quasi certo che le prime macro “LaTeX” siano state scritte per TeX78, la versione prototipo di TeX, che era piuttosto diversa, anche se molte cose sono rimaste.
Ciao
Enrico