He is most remembered for his nighttime journey in April 1775 to warn the colonial militia of the approaching British soldiers before the battles of Lexington and Concord, which was portrayed in Henry Wadsworth Longfellow's poem "Paul Revere's Ride" (1861). However, contemporary accounts by people who were there record that he rode again three weeks later. Revere first learned from a friend in Boston that the British were planning to seize weapons from local stores to use against the colonists. Concerned about this threat to the town's security, Revere then made two trips over 100 miles through hostile territory at night to tell the militias where they could be found. He arrived in Lexington on the evening of 18 April and left four hours later after warning the militiamen at the Old North Bridge near Concord that there were troops heading their way. The next morning, the colonies officially went to war when Massachusetts governor John Hancock ordered guns to be fired upon a British ship that had entered American waters without permission. In his autobiography, Revere described his midnight rides as follows: "I mounted my horse at a quarter past eight and rode through the dark streets to the house of a friend in Boston. I told him what was going on and that we should have war soon." Then he added: "I felt sure I would be back by five in the morning." They weren't.