Final answer:
The poet Emerson used the phrase 'shot heard round the world' to symbolize the impact of the American Revolution on other nations. It inspired people in other countries, like France, to fight for their own independence and democratic rights.
Step-by-step explanation:
The phrase 'shot heard round the world' refers to the gunshot that marked the beginning of the American Revolution. It is a literary metaphor used by the poet Ralph Waldo Emerson to symbolize the impact and significance of the American Revolution not only on the United States but also on other nations. The shot is called 'heard round the world' because it inspired people in other countries, such as France, to fight for their own independence and democratic rights.