The returns told the story of the road. The British counted 273 casualties, 73 killed, 174 wounded, and 26 missing, out of the roughly 1,700 to 1,900 men engaged once Percy's brigade is included: about one man in seven. The Americans lost around 95, 49 of them killed, about 40 wounded, and a handful missing, out of the 3,500 to 4,000 who fought in relays across the day. And the distribution mattered as much as the totals. The green and the bridge, the two famous places, account for a few dozen of those casualties between them. Nearly everything else happened on the 16 miles home, and the single worst town was Menotomy, which no one had planned to fight over at all.

The bitter joke of it was that Lieutenant Colonel Smith's regulars had done their job. They had executed the written orders of General Thomas Gage, the British commander in Boston, almost to the letter, the no-plunder clause excepted: marched to Concord, destroyed what stores they could find, and behaved correctly in the town itself. It did not matter. The stores had been gone for two weeks, 273 men were down, and the army that had marched out to prevent a war marched back into a siege.

The British officers understood immediately what they had met. Percy, the relief commander who had watched the militia work all afternoon, men taking real risks to fire from close range, companies relieving each other town by town, wrote a letter to a fellow general the very next day, and it is the most honest British verdict on April 19.

Whoever looks upon them as an irregular mob will find himself much mistaken. They have men amongst them who know very well what they are about...

He went on: the rebels were "determined to go through with it," and the insurrection would not "turn out so despicable as it is perhaps imagined at home." Smith, nursing his thigh wound, read the same day the other way, sneering in his report to Gage that "Notwithstanding the enemy's numbers, they did not make one gallant attempt during so long an action." Both verdicts landed on Gage's desk within days. Percy's was the one that aged well.

The other battle began before the gunsmoke cleared, and it was fought with paper. Both sides understood within hours that who fired first at Lexington mattered as much as who won the road, and the dueling sworn statements that resulted are why the question can never be honestly resolved: they were produced as weapons, not as evidence. Within days the Provincial Congress (the rebels' own assembly) had collected roughly a hundred depositions, expressly assembled to prove the regulars fired first, and had an account on a fast schooner to Britain; the American version ran in London newspapers nearly two weeks before Gage's official report arrived. Gage's counter-narrative swore the rebels began it, and carried the scalping rumor from the North Bridge along with it; the Congress's answer included sworn statements from the two men who had buried the bodies at the bridge: "neither of those persons were scalped, nor their ears cut off." Strip the instruments away and what remains is the one honest line from the green: a captured British officer who was there could not say which side fired first.

What could not be spun was the siege. The militia companies that broke off at Charlestown Neck on the evening of the 19th did not disband; they camped, and more kept coming, militia converging from four colonies, until the lines ran in an arc from Roxbury to Chelsea and Boston was a garrison town cut off by land. Loose command of the gathering settled on the American general Artemas Ward the next day. The siege of Boston would last from April 19, 1775, to March 17, 1776, and its first great battle came just two months in, when the army outside the town met the regulars again on the hills above Charlestown at Bunker Hill. Pitcairn, the marine major whose advance companies had walked onto Lexington green at dawn, died there, leading his marines up Breed's Hill. Parker, the Lexington captain, too sick to fight by June, died of his tuberculosis that September, age 46.

Memory went to work on the day almost as fast as the propaganda had. The boulder on Lexington green that has Parker saying "Stand your ground; don't fire unless fired upon" carries a much-later recollection, not anything he is known to have said; his actual sworn deposition, taken for the Congress's own campaign yet claiming only dispersal and no firing, is better testimony anyway. The statue by the green is an idealized young minuteman, not a portrait; no likeness of Parker exists. And the poet Ralph Waldo Emerson's shot that rang round the world belongs to the bridge, written sixty-two years after the fact for the hymn sung at the dedication of the bridge monument. The day itself needs none of it. About 700 professional soldiers went out to confiscate a rebellion's hardware, an organized countryside fought them home from behind its stone walls, and by morning the king's army in America was surrounded in its own headquarters town.