I'd say the combustion engine, even though it was toyed with in the mid-west during the cowboy era, it wasn't until after the Civil War in which it was a fully effective gasoline powered engine.
Answer:
"By stipulating and observing four main treaties, the relationship between Rome and Carthage was one of tolerance for centuries. Carthage and Rome also concluded two treaties to end the First and Second Punic War in 241 BC and 201 BC, by which time the relationship between the powers had changed considerably."
Explanation:
D is the answer of this question