American Revolution/Lexington and Concord
Before the Battles 
The Battles of Lexington and Concord are generally considered the start of the American Revolution. British General Thomas Gage, the military governor and commander-in-chief, received instructions, on April 14, 1775, from Secretary of State William Legge, the Earl of Dartmouth to disarm the rebels, who had supposedly hidden weapons in Concord, and to imprison the rebellion's leaders.
On the morning of April 16, Gage ordered a mounted patrol of about 50 men under the command of Major Mitchell of the 5th Regiment into the surrounding country to intercept messengers who might be out on horseback. This patrol behaved differently from patrols sent out from Boston in the past, staying out after dark and asking travelers about the location of Samuel Adams and John Hancock. This had the unintended effect of alarming many residents and increasing their preparedness. The Lexington Militia in particular began to muster early that evening, hours before receiving any word from Boston.
Lieutenant Colonel Francis Smith received orders from Gage on the afternoon of April 18 with instructions that he was not to read them until his troops were underway. They were to proceed from Boston "with utmost expedition and secrecy to Concord, where you will seize and destroy… all Military stores… But you will take care that the soldiers do not plunder the inhabitants or hurt private property."
The rebellion's ringleaders – with the exception of Paul Revere and Joseph Warren – had all left Boston by April 8. They had received word of Dartmouth's secret instructions to General Gage from sources in London long before they had reached Gage himself. Samuel Adams and John Hancock had fled Boston to the Hancock-Clarke House, home of one of Hancock's relatives in Lexington where they thought they would be safe.
The Massachusetts Militia had indeed been gathering a stock of weapons, powder, and supplies at Concord, as well as an even greater amount much further west in Worcester, but word reached the Colonists that British officers had been observed examining the roads to Concord. On April 8, they instructed people of the town to remove the stores and distribute them among other towns nearby.
Warning the Colonists 
Between 9:00 and 10:00 p.m on the night of April 18, 1775, Joseph Warren told William Dawes and Paul Revere that the King's troops were about to embark in boats from Boston bound for Cambridge and the road to Lexington and Concord. Warren's intelligence suggested that the most likely objectives of the British Army's movements later that night would be the capture of Samuel Adams and John Hancock. They worried less about the possibility of regulars marching to Concord. The supplies at Concord were safe, after all, but they thought their leaders in Lexington were unaware of the potential danger that night. Revere and Dawes were sent out to warn them and alert Colonists in nearby towns.
Dawes covered the southern land route by horseback across Boston Neck and over the Great Bridge to Lexington. Revere first gave instructions to send a signal to Charlestown and then he traveled the northern water route. He crossed the Charles River by rowboat, slipping past the British warship HMS Somerset at anchor. Crossings were banned at that hour, but Revere safely landed in Charlestown and rode to Lexington, avoiding the British patrol and later warning almost every house along the route. The warned men and the Charlestown colonists dispatched additional riders to the north.
After they arrived in Lexington, Revere, Dawes, Hancock, and Adams discussed the situation with the militia assembling there. They believed that the forces leaving the city were too large for the sole task of arresting two men and that Concord was the main target. The Lexington men dispatched riders in all directions (except south), and Revere and Dawes continued along the road to Concord. They met Samuel Prescott at about 1:00 a.m. In Lincoln, these three ran into a British patrol led by Major Mitchell of the 5th Regiment and only Prescott managed to warn Concord. Additional riders were sent out from Concord.
Revere and Dawes, as well as many other alarm riders, triggered a flexible system of "alarm and muster" that had been carefully developed months before, in reaction to the British colonists' impotent response to the Powder Alarm. "Alarm and muster" was an improved version of an old network of widespread notification and fast deployment of local militia forces in times of emergency.
Around dusk, General Gage called a meeting of all of the senior officers of his army at the Province House. He informed them that orders from Lord Dartmouth had arrived, ordering him to take action against the colonials. He also told them that the senior colonel of his regiments, Lieutenant Colonel Smith, would command, with Major John Pitcairn as his executive officer.
The British began to awaken their troops at 9 p.m. on the night of April 18 and assembled them on the water's edge on the western end of Boston common by 10 p.m.
As the British Army's advance guard under Pitcairn entered Lexington at sunrise on April 19, 1775, 77 Lexington militiamen, led by Captain John Parker, emerged from Buckman Tavern and stood in ranks on the village common watching them, and spectators watched from along the side of the road. Parker was later supposed to have made a statement that is now engraved in stone at the site of the battle: "Stand your ground; don't fire unless fired upon, but if they mean to have a war, let it begin here."
Rather than turn left towards Concord, Marine Lieutenant Jesse Adair, at the head of the advance guard of light infantry companies from the 4th, 5th and 10th Regiments of Foot, decided on his own to protect the flank of his troops by first turning right and then leading the companies down the common itself in a confused effort to surround and disarm the militia. These men ran towards the Lexington militia loudly crying "Huzzah!" to rouse themselves and to confuse the militia. Major Pitcairn arrived from the rear of the advance force and led his three companies to the left and halted them. The remaining companies lay behind the village meeting house on the road back towards Boston.
Pitcairn then apparently rode forward, waving his sword, and yelled "Disperse, you rebels; damn you, throw down your arms and disperse!" Captain Parker told his men instead to disperse and go home, but, because of the confusion, the yelling all around, and due to the raspiness of Parker's tubercular voice, some did not hear him, some left very slowly, and none laid down arms. Both Parker and Pitcairn ordered their men to hold fire, but suddenly a shot was fired from a still unknown source.
Some witnesses among the regulars reported the first shot was fired by a colonial onlooker from behind a hedge or around the corner of a tavern. Some observers reported a mounted British officer firing first. Both sides generally agreed that the initial shot did not come from the men on the ground immediately facing each other.
Witnesses at the scene described several intermittent shots fired from both sides before the lines of regulars began to fire volleys without receiving orders to do so. A few of the militiamen believed at first that the regulars were only firing powder with no ball, but then they realized the truth, and few, if any, in the militia managed to load and return fire. The rest ran for their lives.
The light infantry companies under Pitcairn at the common got beyond their officers' control. They were firing in different directions and preparing to enter private homes. Upon hearing the sounds of muskets, Colonel Smith rode forward from the grenadier column. He quickly found a drummer and ordered him to beat assembly. The grenadiers arrived shortly thereafter, and, once they were rounded up, the light infantry were then permitted to fire a victory volley, after which the column was reformed and marched towards Concord. At Lexington, the British had suffered one killed, while the colonists had suffered 8 killed.
The militiamen of Concord, uncertain of what had actually transpired at Lexington, were not sure whether to wait until they could be reinforced by troops from towns nearby, or to stay and defend the town, or to move east and greet the British Army from superior terrain. As the regulars began to approach, they did all of these. The Minutemen watched from a hill as Smith deployed light infantry against them. They began a series of marching retreats into the town. Some had occupied a hill in the town and now argued about what to do next, while others approached with the regulars behind them. The Lincoln militia arrived and joined in the debate. Caution prevailed, and Colonel James Barrett surrendered the town of Concord and led the men across the North Bridge to a hill about a mile north of town, where they could continue to watch the troop movements of the British.
Using the detailed information provided by Loyalist spies, the grenadier companies searched the small town for military supplies. When the grenadiers arrived at Ephraim Jones's tavern, by the jail on the South Bridge road, they found the door barred shut, and Jones refused them entry. According to reports provided by local Tories, Pitcairn knew cannon had been buried on the property, so, holding the tavern keeper at gunpoint, he ordered him to show him where the guns were buried. These turned out to be three massive pieces, firing 24-pound shot, much too heavy to use defensively, but very effective against fortifications, and capable of bombarding the island city of Boston from the mainland.
Colonel Barrett's troops, upon seeing smoke rising from the village square and seeing only a few companies directly below them, agreed to march back towards town from their vantage point on Punkatasset Hill to a lower, closer flat hilltop about 300 yards (300 m) from the North Bridge over the Concord River. This land belonged to Major John Buttrick, who led the Minuteman units under Barrett. It was also their muster (training) field. Two British companies from the 4th and 10th held this position, but they marched in retreat down towards the bridge and yielded the hill to Barrett's men.
Five full companies of Minutemen and five of militia from Acton, Concord, Bedford and Lincoln occupied this hill along with groups of other men streaming in, totaling at least 400 against the light infantry companies from the 4th, 10th, and 43rd Regiments of Foot under Captain Laurie, a force totaling about 90–95 men. Barrett ordered the Massachusetts men to form one long line two deep on the highway leading down to the bridge, and then he called for another consultation. While overlooking North Bridge from the top of the hill (which would after 1793 have a road built on it called Liberty Street), Barrett and the other Captains discussed possible courses of action.
At this moment, they first saw the smoke from the burning gun carriages and barrels rising over Concord, and many thought the regulars had set the town alight. Barrett ordered the men to load their weapons but not to fire unless fired upon. Then he ordered them to advance. Both British companies used as guards were ordered to retreat back across the North Bridge, and one officer then tried to pull up the loose planks of the bridge to impede the colonial advance. Major Buttrick began to yell at the regulars to stop harming the bridge. The Minutemen and militia advanced in column formation on the light infantry, keeping to the highway only, since the highway was surrounded by the spring floodwaters of the Concord River.
The inexperienced Captain Walter Laurie of the 43rd Regiment of Foot, in nominal command of this little detachment, then made a poor tactical maneuver. When he found his summons for help to the grenadiers downtown produced no results, he ordered his men to form positions for "street firing" behind the bridge in a column running perpendicular to the river. This formation was appropriate for sending a large volume of fire into a narrow alley between the buildings of a city, but not for an open path behind a bridge. Confusion reigned as regulars retreating over the bridge tried to form up in the street-firing position of the other troops. Lieutenant William Sutherland, who was in the rear of the formation, saw Laurie's mistake and ordered flankers to be sent out. But he was from a company different from the men under his command, and only four soldiers obeyed him. The remainder tried as best they could in the confusion to follow the orders of the superior officer.
Shots soon rang out and the battle began. The few front rows of colonists, bound by the road, and blocked from forming a line of fire, managed to fire over each others' heads and shoulders at the regulars. The musket balls plunged down out of the sky down into the mass of regular troops. Four of the eight British officers and sergeants at the bridge, leading from the front of their troops as officers did in this era, were wounded by the volley of musketry coming from the British colonists.
The regulars found themselves trapped in a situation where they were both outnumbered and outmaneuvered. Leaderless, terrified at the superior numbers of the enemy, their spirit broken, never having experienced combat before, they abandoned their wounded, and fled to the safety of the approaching grenadier companies coming from the town center.
Continued Fighting 
The colonists were stunned by their success. No one had actually believed each side would shoot and kill each other. Some advanced; many more retreated; and some went home to see to the safety of their homes and families. Colonel Barrett eventually began to recover control and chose to divide his forces. He moved the militia back to the hilltop 300 yards (270 m) away and sent Major Buttrick with the Minutemen across the bridge to a defensive position on a hill behind a stone wall.
Smith, leader of the British expedition, heard the exchange of fire from his position in the town moments after he had received a request for reinforcements from Laurie. Smith assembled two companies of grenadiers to lead towards the North Bridge himself. As these troops marched, they met the shattered remnants of the three light infantry companies running towards them. Smith was concerned about the four companies which had been at Barrett's. Their route to return safely was now gone. Then he saw the Minutemen in the distance behind their wall, and he halted his two companies and moved forward with only his officers to take a closer look.
These men, unaware of what had happened, marched back from their fruitless search of Barrett's farm. They passed unharmed by Barrett's militia on the muster field and through the tiny battlefield, saw dead and wounded comrades lying on the bridge, including one who looked to them as if he had been scalped, which angered and shocked the British soldiers. They then passed sullenly over the bridge, unharmed by Buttrick's Minutemen. The regulars all returned to the town by 10:30 a.m. Even after a small skirmish, and with superior numbers, the British colonists still did not fire yet unless fired upon, and this time the regulars did nothing to provoke them. The British Army continued to destroy colonial military supplies in the town, ate lunch, reassembled for marching, then left Concord after noon.
As the day wore one, there were more conflicts between the regulars and the colonists. Three British companies were ambushed by the colonists, and the remaining officer even considered surrendering, until a full brigade with artillery of about 1,000 men under the command of Hugh, Earl Percy arrived to rescue them.
The fighting grew more intense as Percy's forces crossed from Lexington into Menotomy. Fresh militia poured gunfire into the British ranks from a distance, and individual homeowners began to fight from their own property. Some homes were also used as sniper positions. It now turned into a soldier's nightmare: house-to-house fighting.
Percy lost control of his men, and British soldiers began to commit atrocities to repay for the purported scalping at the North Bridge and for their own casualties at the hands of a distant, often unseen enemy. Based on the word of Pitcairn and other wounded officers from Smith's command, Percy learned that the Minutemen were using stone walls, trees and buildings in these more thickly settled towns closer to Boston to hide behind and shoot at the column. Percy proceeded to give orders to the flank companies to clear these colonial militiamen out of such places.
Many of the junior officers in the flank parties had difficulty stopping their exhausted, enraged men from killing everyone they found inside these buildings. The British troops crossed the border into Cambridge, and the fight grew more intense. Fresh militia arrived in close array instead of in a scattered formation, and Percy used his two artillery pieces and flankers at a crossroads called Watson's Corner to inflict heavy damage on them.
A large militia force arrived from Salem and Marblehead. They might have cut off Percy's route to Charlestown, but these men halted on nearby Winter Hill and allowed the British to escape. Some accused the commander of this force, Colonel Timothy Pickering, of permitting the troops to pass because he still hoped to avoid war by preventing a total defeat for the regulars.
In the morning, Gage awoke to find Boston besieged by a huge militia army, numbering 20,000, which had marched from throughout New England. This time, unlike during the Powder Alarm, the rumors of spilled blood were true, and the Revolutionary War had begun. The militia army continued to grow as surrounding colonies sent men and supplies. The Continental Congress would adopt and sponsor these men into the beginnings of the Continental Army. Even now, after open warfare had started, Gage still refused to impose martial law in Boston. He persuaded the town's selectmen to surrender all private weapons in return for promising that any inhabitant could leave town.