One of the most significant challenges is building an airplane had to do with "propulsion", since the technology that allowed motors to have enough energy to lift an airplane into the sky with a passenger wasn't available for most of history.
The right answer for this question is the enslaved African Americans. This was a form of resistance against slavery, where slaves became less efficient on purpose in order to rebel against their masters a lot.
They should’ve been together and fought when they needed to to get more things
