Which poet is credited with coining the phrase "shot heard round the world"?

The phrase "shot heard round the world" is famously associated with Ralph Waldo Emerson. It originates from his poem "Concord Hymn," written in 1837. This phrase refers to the first gunfire which sparked the American Revolutionary War during the battles of Lexington and Concord in April 1775. Emerson's use of this expression emphasizes the historical significance of the event, suggesting that it resonated far beyond its immediate locality, symbolizing a pivotal moment in the fight for independence.

In contrast, Walt Whitman, Robert Frost, and Langston Hughes made substantial contributions to American literature and poetry, but they are not linked to this particular phrase or its context within American history. Whitman is known for his innovative free verse and exploration of self and democracy, Frost for his rural New England themes and use of traditional forms, and Hughes for his role in the Harlem Renaissance and his focus on the African American experience. None of these poets can be directly associated with the phrase "shot heard round the world."