This expression "the map is not the territory" first appeared in print in a paper that Alfred Korzybski gave at a meeting of the American Mathematical Society in New Orleans, Louisiana in 1931.
LaRouche loves maps ("genealogical trees") and hates facts ("territory"), which he calls "factoids"
Here are a few samples:
1. Alfred Korzybski coined the expression in "A Non-Aristotelian System and its Necessity for Rigour in Mathematics and Physics," a paper presented before the American Mathematical Society at the New Orleans, Louisiana, meeting of the American Association for the Advancement of Science, December 28, 1931. Reprinted in Science and Sanity, 1933, p. 747–61.