Final answer:
Captain Preston stated that Private Montgomery fired the first shot after a colonial militiaman shot at the British troops in Lexington, which marked the beginning of the American Revolution.
Step-by-step explanation:
Captain Preston told the court that Private Montgomery fired the first shot after a colonial militiaman fired upon the British troops. This event took place when Major Pitcairn approached Lexington, encountering the colonial militia assembled there. According to Colonel Smith's account to General Gage, the militia was drawn up in military order and appeared to be loaded with weapons. Despite the British troops advancing without intention to injure, just to inquire about the militia's assembly, the situation escalated when a shot was fired by one of the militiamen. Following this, several militiamen fired from behind a wall among the soldiers, leading to the British troops returning fire and killing several colonists. This tragic series of events marked the outbreak of violent conflict and was a catalyst for the subsequent American Revolution. It also inspired other global movements for independence, such as the French Revolution, signifying its historical significance as the 'shot heard round the world'.