Gustave Whitehead not only made engines, used them to fly, and wrote letters to the editor about them in 1901-1902 through 1911, but he was actively developing and selling them to other inventors. He was interviewed in person and displayed his engines, and there are many photos of them. Aviation pioneer Charles Witteman was one of his customers who said Whitehead was a genius. Wikipedia is definitely not the source of all knowledge, nor is what we have been taught the last word. History is always catching up to what the realities actually were.
Gustave Whitehead First to Fly