In front of Lexington, Massachusetts’s Town Hall is a large sign that announces, every day, the number of days until April 19, 2025, the 250th anniversary of the first battle between British Army soldiers and local militia units that began America’s War for Independence. Neither the original event’s location nor its date was entirely a surprise, either in Massachusetts or as far south as Virginia. But to understand why this clash happened, and what effect it had, one must look at a chain of earlier events, and the effect that each of these had on the thoughts and beliefs of many thousands of British Americans.

　　To put the question in its starkest terms, what persuaded thousands of Massachusetts farmers to risk their own lives, and the lives and security of their families and communities, by silently protesting and then violently attacking the incursion into their rural world of several hundred heavily armed and highly trained soldiers who were commanded by a King and Parliament that these same farmers had long accepted as their own legitimate government? To answer this question, though, one must address several others.

　　First, how did many thousands of British North Americans come to believe that they had a right to stage an armed rebellion against a government that they had regarded as legitimate since their youth, and to which many had even pledged their loyalty with pride and defended as provincial soldiers in Britain’s wars with France?

　　Second, why did these convictions—the right to rebellion, and finally the absolute rightness of rebellion in 1775—become stronger in Massachusetts than in any other British North American colony?

　　Third, why did so many colonists, first in Massachusetts and then in nearly all these colonies, become convinced that they could rebel successfully against Great Britain, commonly regarded in the late eighteenth century as the strongest imperial nation in the world?

　　Finally, were there certain events and developments, peculiar not just to Massachusetts, but to Concord, Massachusetts, which made it likely that armed rebellion would first happen there and not elsewhere, and in the spring of 1775, rather than earlier or later?

　　A satisfactory answer to the first question is complex, but hardly hidden or obscure, either in 1775 or today. Most literate (and many illiterate) British North Americans, and most Britons, knew that their government was a constitutional monarchy, a unique fusion of a reigning king or queen and a Parliament whose authority, from its center in Great Britain, extended outward to over two dozen settler colonies of various sizes, ages, economies, and demographies, and dozens of smaller outposts, spread across several continents. The vital role of privileged subjects of the monarch in limiting his or her authority developed gradually in England from at least as early as Magna Carta (1215) and the ensuing thirteenth-century parliaments. And after England’s “Glorious Revolution” of 1689, it included the right of all titled nobles, and many commoners, elected by many other commoners, to sit in Parliament and help shape both local and national policy.

　　From the early seventeenth century many English settler colonies in North America were granted their own legislative assemblies in which they could work with royally appointed governors to develop their own local laws. These bodies, like Britain’s House of Commons, were elected, but by a relatively larger popular base than in England, Scotland, and Wales. Both Lexington and Concord, and over two hundred other Massachusetts towns, sent delegates every year to their provincial assembly. And all of these legislatures, large and small, in Britain and North America, had the power of the purse. No one could be taxed, and nothing could be funded, neither the British army and navy nor the Massachusetts militia, without the approval of both legislatures and executives, monarchs, or their appointed representatives. Every British soldier who marched into Lexington and Concord on April 19, 1775, was there because George III and Parliament had paid him to be there. And every Massachusetts militiaman who opposed him was there because his town and his province had funded an organized militia, and paid for some of its weapons and ammunition, that enabled his resistance.

　　But these sequential and coordinated British and American histories do not quite answer our first question: Why did the minutemen of Lexington and Concord believe they had a right to resist the British redcoats? After all, from the commonly held—but by no means universal—British perspective in 1775, their King and Parliament had followed the rules of constitutional government, passing certain laws for the benefit of the entire British empire, and imposing their rule by force only when certain British North Americans—particularly Bostonians—had resisted those laws in the 1760s and 1770s, culminating in the Boston Tea Party (1773) and Britains swift response, the Boston Port Act and the Massachusetts Government Act (1774), which placed Boston, and to a lesser extent the entire province of Massachusetts Bay, under strict Parliamentary authority and, at least for the foreseeable future, military rule. The right upon which the resisting militiamen appealed would be elegantly expressed by the Declaration of Independence: “Whenever any Form of Government becomes destructive of these ends [securing Life, Liberty, and the Pursuit of Happiness], it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness.”

　　The preceding decade of growing friction with Britain had affirmed Massachusetts’s commitment to the right of self-government, amplified by its devotion to the powers granted in the province’s Charter.

　　The altering and abolishing would not begin until 1776, but the armed resistance that made it possible began in April 1775. Where did the right to do this come from? Taking a long look back across British and European history, this idea developed on two parallel tracks, in political action and in political thought. In England itself there were two revolts by Parliament against the monarchy, the first igniting the English Civil War and culminating in the execution of King Charles I (1649), and the second beginning with the expulsion of his son, James II, from the throne in 1688, followed by the revolutionary settlement of 1689. This latter event established the principle that all legislation must be approved by elected Parliaments. The one remaining question, for British North American settler colonies, was whether this power was also enjoyed by their elected assemblies.

　　As Parliament grew more powerful, a rich literature in Britain and America explored every aspect of political sovereignty. Over time, several authors in Britain, and the great majority of writers in America, favored extending this power beyond Britain’s borders. In 1689 the contract theorist John Locke, the best known of English political writers in colonial America, affirmed the general right of revolution that Thomas Jefferson declared for America in 1776. More broadly, in Italy, Switzerland, Holland, France, and Britain, from the sixteenth through the eighteenth centuries, several writers revived and explored the legal legacy of the ancient Greek and Roman traditions of republican government. Some of these writers, like Machiavelli, Hobbes, Grotius, and Vattel, were read only by a few learned lawyers in America, but others, such as Sidney, Harrington, Montesquieu, and even Rousseau, and of course Locke, found more readers across the Atlantic Ocean.

　　And in Massachusetts, Virginia, and Pennsylvania, American writers, beginning in the 1760s, asserted the right of provincials to shape their own taxes and laws free of Parliamentary interference. In 1773 this became the official position of the Massachusetts assembly. In the fall of 1774, building on the bold declarations of Virginia’s Fairfax Revolves and Massachusetts’s Suffolk Resolves, the First Continental Congress extended this claim to every British North American colony. In March 1775, just weeks before Lexington and Concord, John Adams, adopting the pseudonym Novanglus, wrote a series of essays asserting that both English and American history proved that the colonies’ bond with Britain was simply a voluntary allegiance to King George III, one that they could dissolve whenever the monarch failed to meet his royal obligation to protect his subjects and guarantee their rights.

　　The second question is why Massachusetts became the first colony to rebel against British authority. Nearly every North American colony had experienced some friction with Britain in the previous decade, and in several provinces, the voices and occasional acts of resistance had been strong and persistent. But Massachusetts, founded by religious dissenters, had an exceptionally strained relationship with the imperial metropole almost from the beginning. It was nearly independent of London through most of the seventeenth century, and in 1691, when it had finally submitted to royal authority, it received in turn a charter that gave it an unusual degree of autonomy. The province had, with Virginia, one of the two largest legislative assemblies in America, and the largest and most independent governor’s council. It also had among the fewest British-born—or even British-educated—officials of any colony.

　　This arrangement nurtured an exceptionally confident and assertive political culture, one that Britain found increasingly difficult to control from the Stamp Act crisis (1765), through the Boston Massacre (1770), to the Boston Tea Party (1773), with each crisis marked by one or more popularly supported mass demonstrations resulting in the destruction of property or the loss of life. An attempt to control Boston by imposing British army units on the city in 1768–70 only increased local animosity, and the next military occupation, in 1774, quickly became central to the political alteration that led directly to Lexington and Concord.

　　In the spring of 1774, after deciding to punish Boston for the Tea Party by closing its port to all commerce until the town paid the East India Company for the destroyed cargo, Parliament took an even more aggressive measure, the Massachusetts Government Act. Invalidating the Massachusetts Charter of 1691, it replaced the province’s previously elected governor’s council with one appointed by the Crown and curtailed the powers of both local sheriffs and town governments. Even before this constitutional alteration, the King had appointed as governor of the province General Thomas Gage, the commander of the British army in North America, and sent him to Boston with several regiments of Redcoats, and several warships. Local leaders briefly attempted to cooperate with Gage, but by September the governor became convinced that it was too dangerous to convene the provincial assembly.

　　Thereafter, Massachusetts lived under two governments. The new regime in the town of Boston, enforced by over 3,000 British soldiers, controlled just a few thousand acres of coastline within the range of naval canon. But from October 1774 a series of provincial conventions, defiantly operating under the 1691 Charter and meeting in safely interior communities, notably Cambridge and Concord, presided over some two hundred towns in every part of the province, including the district of Maine. Royal government in Massachusetts had effectively and permanently ended.

　　But the potential for escalating armed conflict was just beginning. Governor Gage was determined to assert British authority over the rebellious province, and on September 1, he sent a few soldiers to seize ammunition stored in a small powder house a few miles from Boston. The reaction was explosive. Rumors spread through nearby towns that the British were going to attack the civilian population of Boston, and the next day thousands of armed militiamen gathered in Cambridge, determined to attack the British army in the city. Only the spirited appeals to restraint by the province’s Patriot leaders, and their expression of gratitude to the militiamen for their resolve to defend the province’s liberty, persuaded the men to return home. Had they assaulted Gage’s forces, the outcome, for the militia, for the British army, and for the civilian population of Boston could not have been good.

　　In the following week, Patriot leaders from several towns near Boston drafted and endorsed the Suffolk Resolves, which declared that the province had no obligation to observe the Coercive Acts or to obey General Gage’s commands. And they formally put their militia on a wartime footing and designated a portion of each town’s militia as an elite corps of “Minutemen,” who would assemble quickly to defend the community. The Patriot rider Paul Revere was immediately dispatched to Philadelphia with the Resolves, where the First Continental Congress promptly approved them. Massachusetts now had an intercolonial endorsement for its preparation for armed rebellion.

　　But the militia’s willingness to attack Gage’s regiments in September prompts our third question: Why did Massachusetts soldiers, and after Lexington, the soldiers of a dozen other colonies to the north, south, and west, believe they could face and defeat the British army? In part, their conviction of the rightness of their cause emboldened them (just as Abraham Lincoln would assert eighty-five years later, in his Cooper Union address defending the Republican Party’s campaign to limit American slaveholding, that “right makes might”). And by 1774 many Patriot leaders had thought about the challenge before them, and had taken measure of their own strength.

　　In February 1775, some five months after the “Massachusetts Powder Alarm” rising of the militia, but just over two months before Lexington and Concord, John Adams, in his third Novanglus letter, tallied up the militia forces in Massachusetts, and the potential militia forces in the extensive backcountry of several other colonies, and concluded that Americans could put tens of thousands of men in the field. (Massachusetts alone would put tens of thousands of men under arms over the next five years, first as militiamen, and then as the largest state contribution to the Continental Army). Moreover, most Patriot leaders seem to have understood from the outset of the colonies’ conflict with Britain that the essential ingredient in their success would be unity. In the ensuing War for Independence, the American rebels would enjoy other advantages as well, in particular the defensive wall of the Atlantic Ocean, and the support in several of the rebelling colonies/states, of extensive interior territory hostile to British invasion, both of which made most British incursions difficult and expensive. These same advantages would play a role as early as Lexington and Concord, but it is not clear how aware the Massachusetts militiamen were, in April 1775, of these strategic assists to their bravery.

　　What Americans have done with that independence, and what we still do, every day, is an ever-evolving, never-resolved question.

　　The stage was now set, at the end of an unusually mild winter that encouraged militia training, for armed conflict. The preceding decade of growing friction with Britain had affirmed Massachusetts’s commitment to the right of self-government, amplified by its devotion to the powers granted in the province’s Charter. And the repeated occupation of Boston by British regiments intensified the fear of standing armies, a concern of all British and American lovers of liberty. If a violent clash was ever to come, it would come in Massachusetts, and many political leaders to the south knew it. On March 23, Virginia’s Patrick Henry, in his most famous speech—“Give me liberty or give me death!”—predicted that “the next gale that sweeps from the North will bring to our ears the clash of resounding arms!”

　　The only questions, before the event itself, are why on April 19, and why at Lexington and Concord? These are the easiest to answer.

　　On April 12, General Gage received orders from his impatient London superiors to press the rebels more aggressively. His scouts had already informed him that the militia had a large store of arms and ammunition at Concord, including several field pieces. On the 14th he began planning an armed expedition to seize these weapons, and on the evening of the 18th, he sent some 700 infantrymen and grenadiers across the Charles River, where they began their sixteen-mile march to Concord. Lexington, halfway along the road to Concord, was not a military objective of the British forces, but the Patriots were concerned that the British would seize two of their leaders, Samuel Adams and John Hancock, who were then staying in the town. Paul Revere, sent out with other Patriot riders to warn of the army’s approach, advised Adams and Hancock to move farther inland. And the town’s militia chose to make a silent stand as the Redcoats passed by. On Lexington Green just before sunrise on the 19th, the minutemen stood in lines as the British column approached, when some person, British or American, unidentified to this day, fired a shot, and British soldiers poured onto the Green and began to fire. At Lexington, all the casualties were American.

　　At Concord, a few hours later, the militiamen were more aggressive, but at first, still restrained in their actions. They moved some of their arms out of the town center ahead of the British column, and sunk others in the town pond. And when a large militia force gathered to the north saw smoke from a British fire set to destroy other arms, they feared the soldiers were going to torch the whole town. Approaching North Bridge, they fired and forced back the few British guarding the crossing, and here the few casualties were mostly British. But when the regulars began their return march to Boston, there had not really been a battle, and the Massachusetts farmers could have let the invaders depart in peace.

　　At this point, just a mile into the return march, the militia gathering from many towns, now numbering over one thousand and growing, suddenly began firing at the soldiers from any relatively safe position along the route they could find, and kept firing, with more town militia units joining the conflict every mile, all the way to Cambridge and Charlestown, when approaching darkness and the proximity of British warships finally ended the carnage. It was this action—perhaps the sudden release of years of rising anger at more menacing British rule—that made Lexington-Concord the event that it became: a massive clash of two opposing, irreconcilable forces. America’s reaction, a rush to arms in all thirteen rebelling colonies, was instantaneous. A constitutional crisis, erupting in the summer of 1774, had finally become a violent conflict between the full forces of Great Britain and thirteen united North American colonies. The War for American Independence had begun.

　　In the larger context of American history, no single event, not even Lexington-Concord, can ever fully define the American Revolution; it certainly did not initiate the complex political, social, and cultural developments of that era. But it did begin America’s War for Independence. What Americans have done with that independence, and what we still do, every day, is an ever-evolving, never-resolved question. Perhaps the most famous testimony to this reality is the closing stanza of Longfellow’s celebrated verse, “Paul Reveres Ride,” published on the eve of the Civil War. His poem soon became a staple of public school recitations, but his goal was more immediate:

　　So through the night rode Paul Revere;

　　And so through the night went his cry of alarm

　　To every Middlesex village and farm, –

　　A cry of defiance and not of fear,

　　A voice in the darkness, a knock at the door,

　　And a word that shall echo forevermore!

　　For, borne on the night-wind of the Past,

　　Through all our history, to the last,

　　In the hour of darkness and peril and need,

　　The people will waken and listen to hear

　　The hurrying hoof-beats of that steed,

　　And the midnight message of Paul Revere.

　　This lesson, always timely in any free republic, has never been more urgently needed than in 2025, the 250th anniversary of Lexington and Concord.