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: U.S. RIVERS 
Clue: The name of this river, famous in song, may be a corruption of the Spanish for "little Saint John"
the swanee

Category: PUBLICATIONS 
Clue: Henry Nichols' "Four Seasons" engraving has appeared on the cover of this publication each year since 1851
farmers\' almanac

Category: WORLD LEADERS 
Clue: Shortly after he received the 1990 Nobel Peace Prize, his country ceased to exist

mikhail gorbachev