General fact: 56 is the maximum speed of analog data transmission over a POTS in the 20th century measured in kbit/s.
Mathematical fact: 56 is the number of reduced 5×5 Latin squares.
Trivia: 56 is the number of layers of the Universe according to Aristotle (Earth plus 55 crystalline spheres above it).
Historical date: February 25th is the day in 1797 that Colonel William Tate and his force of 1000-1500 soldiers surrender after the Last Invasion of Britain.