This gets into the question of when something can be counted as invented. And what had to come first, for that to happen. We can make a pretty good case for John Fitch building the first steamboat, for example, but that boat was made possible by steam engines becoming efficient enough so that one could be finally small enough to fit on a hull and actually power it upstream.

There was a great deal of research and exploration of aeronautics in the 19th c. , and the Wrights took full advantage of it. The Wrights were fortunate to befriend Octave Chanute, who was of great help in educating them in what had already been learned.. They could read of Otto Lilienthal's work with hang gliders. And because others, like Gustav Eiffel, had already developed the wind tunnel, they had an essential tool for their workshop. Internal combustion engines were also being developed, and were taking the place of heavier, less efficient steam engines- and that would be another requirement of powered flight. The Wrights, in other words, were not doing it all from the ground up. ,

However, the reason the Wrights typically get the credit for inventing the airplane is that they solved the problem of control, with their warpable wing, which acted like modern ailerons. Langley , Santos-Dumont and others had been able to build things with lift, sometimes getting them off the ground. But after their aircraft got airborne it was mostly a matter of time and chance as to when the aircraft went astray and came down. Lilienthal , designing his gliders to have a lot of dihedral and swinging his body from side to side ( like a modern hang glider) , had achieved some control and was in pursuit of more: if he hadn't died in a trial, he might have beaten the Wrights for priority. But when the Wrights finally began their demonstrations of their Flyer, there really was no argument as to what they'd accomplished. Previous aviators had managed to show distances of yards and flight times of seconds, before being forced down. When Wilbur demonstrated the Wrights' plane over and over, in Paris in 1908, it was obvious that he could fly laps, figure 8's, and just keep going until he had to stop for gas. Santos-Dumont quickly incorporated the Wrights' warpable wing into his Demoiselle, which made the plane practical enough to be one of the more accessible and so popular designs in the first few years after the Wrights' Paris exhibitions.