What is the first indication that history, in Fahrenheit 451, has been re-written?

In , the first
indication that history has been rewritten occurs when Montag first meets Clarisse and she asks
him about his job. She enquires whether it is true that firemen once used to put out fires
instead of starting them and he replies confidently that this is not the case: houses have
always been fireproof and firemen have always been book-burners.

Later,
Montag recalls these words and hesitantly asks Beatty the same question: have the firemen always
started fires rather than extinguishing them? In response the other firemen, Stoneman and Black,
refer to their rulebooks, which contain brief histories of the Firemen of America (apparently
regarded as authoritative despite the fact that books are illegal). The histories say that the
fire department was started in 1790 to burn English-influenced books in the Colonies and that
the first fireman was Benjamin Franklin. This confirms for the reader that history has been
rewritten. The idea that firemen have always burned books is officially sanctioned with a
falsehood about the role of one of the Founding Fathers, a sworn enemy of censorship, which
shows that Montag was not merely mistaken but indoctrinated.