Final answer:
Paul Revere's ride to warn the American colonists of British movements happened on April 19, 1775.
Step-by-step explanation:
Paul Revere's famous ride to alert the colonists about the approaching British troops took place on April 19, 1775.
The Patriot messengers, including Paul Revere and William Dawes, spread the word that the British were coming, with Revere setting out towards Lexington and Concord. Despite General Thomas Gage's attempts to keep the British movements secret, the colonists were well-informed and prepared for the British arrival, which led to the famous Battles of Lexington and Concord, considered the starting point of the American Revolutionary War.