TASK DEFINITION: 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.
PROBLEM: Category: AMERICAN LITERATURE 
Clue: Controversial even when serialized in the "National Era", it sold over 300,000 copies in book form in 1852

SOLUTION: uncle tom\'s cabin

PROBLEM: Category: MONARCHIES 
Clue: 1 of the 2 largely German-speaking monarchies in the world; they're about 250 miles apart

SOLUTION: liechtenstein & luxembourg

PROBLEM: Category: 20th CENTURY U.S. PRESIDENTS 
Clue: The 2 U.S. presidents whose middle names are also the last names of 2 other presidents

SOLUTION:
ronald wilson reagan & william jefferson clinton