April 19, 1775, was a quiet day in America’s Thirteen Colonies—except for a deadly encounter in Lexington, Mass., between about 80 militiamen and 700 British regulars. Neither side had been expecting a fight, and no one knows who really fired the first shot. But accident or no, it set off one of the greatest social and political experiments in history.
The Battle of Lexington was also the inspiration behind one of America’s best-known poems, the “Concord Hymn” by Ralph Waldo Emerson. Even those unfamiliar with the poem will recognize the line: “Here once the embattled farmers stood/ And fired the shot heard round the world.”
A single act can indeed change the course of history, and Emerson’s line has often been invoked since the poem appeared in 1837. It is particularly associated with the assassination of Franz Ferdinand in 1914 by the Serbian nationalist Gavrilo Princip. Though powerful forces were already building before the Habsburg archduke’s death, Princip’s shot is widely regarded as the blast that set them free.