Yes, I would say that good leadership was key to Imperial Rome's success because to be able to conquer such a vast area north of the Mediterranean stretching from Spain (and England) in the west to Palestine in the east and to be able to exploit the mineral deposits of many of these countries and to control the areas conquered without major rebellions must have required good leadership.
Answer:https://en.wikipedia.org/wiki/List_of_African_Union_member_states_by_political_system
Explanation: it may be wikipedia but right now its your best bet
Whigs, democrats, free-soil party members