 On April 15, he issued orders to hand-picked companies of British Regulars in Boston, relieving them from their usual duties.Concluding that a British movement was imminent, Paul Revere, a messenger for the provincial Sons of Liberty, was sent to Concord on April 16 to warn the inhabitants.Most of the supplies were removed from Concord, and the Minuteman companies were on alert days before the British marched from Boston.