Ted Perry
He has repeatedly and publicly stated he never intended his script to be taken as a real historical document. The actual 1854 speech it is loosely based on survives only through one man's much later written recollection, and says something substantially different from the version now taught in schools and quoted by governments as genuine.
Ted Perry's screenplay for the 1972 film Home; Henry Smith's 1887 recollection of the actual 1854 speech
A screenwriter who wrote an environmentalist speech for a 1972 television film, since quoted worldwide as an authentic nineteenth-century Native American text.