math_fact: 4837 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 4837 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: March 29th is the day in 1957 that the New York, Ontario and Western Railway makes its final run, the first major U.S. railroad to be abandoned in its entirety.