In America you could ba any age to fly a plane but you had to be atleast 18 to join the army some 16 year olds lied about their age to get to fly a plane.
Less than 200 mph.
There are a lot, but these could work: The Industrial Revolution, World War I and World War II. You could also argue that America's status as a world power was evidenced when America's great depression caused a world wide depression.
America minding there own business
America didn't fight in world war 1
it could be the tank or airplane. Probably the plane
america entered the war after pearl harbor
The lightest palne was a dog plane
To try and force the Japanese emperor to surrender so that the second horrid world war could come to an end.
The Ones In World War 1
Me 262
B-17