Q: You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.
Category: HISTORICAL TERMS 
Clue: Historians refer to "the long 19th century", the 125-year span between these 2 events
A:
the french revolution and world war i