Wikipedia's Gustave Whitehead article states "controversy surrounds published accounts and Whitehead's own claims that he flew a powered machine successfully several times in 1901 and 1902, predating the first flights by the Wright brothers in 1903." Connecticut's legislature officially recognized Whitehead as "Father of Connecticut Aviation" in 1968; North Carolina's General Assembly passed a 1985 resolution giving the claim "no credence." Mainstream aviation historians side with the Wright brothers, but the dispute remains live enough to have produced competing state resolutions decades apart.
What would resolve this Physical evidence (a surviving aircraft, verifiable photograph, or independently corroborated eyewitness record) of a genuinely powered, controlled 1901-1902 Whitehead flight, which mainstream aviation historians say does not exist.
OpenWikipedia contributors, Gustave Whitehead (Wikipedia)