Around dusk, General Gage called a meeting of his senior officers at the Province House.
He informed them that instructions 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 meeting adjourned around 8:30 pm, after which Earl Percy mingled with town folk on Boston Common.
According to one account, the discussion among people there turned to the unusual movement of the British soldiers in the town.
When Percy questioned one man further, the man replied, "Well, the regulars will miss their aim."

"What aim?"
asked Percy. "
Why, the cannon at Concord" was the reply.
Upon hearing this, Percy quickly returned to Province House and relayed this information to General Gage.
Stunned, Gage issued orders to prevent messengers from getting out of Boston, but these were too late to prevent Dawes and Revere from leaving.

The British regulars, around 700 infantry, were drawn from 11 of Gage's 13 occupying infantry regiments.
Major Pitcairn commanded ten elite light infantry companies, and Lieutenant Colonel Benjamin Bernard commanded 11 grenadier companies, under the overall command of Lieutenant Colonel Smith.

Of the troops assigned to the expedition, 350 were from grenadier companies drawn from the 4th (King's Own), 5th, 10th, 18th (Royal Irish), 23rd, 38th, 43rd, 47th, 52nd and 59th Regiments of Foot, and the 1st Battalion of His Majesty's Marine Forces.
Protecting the grenadier companies were about 320 light infantry from the 4th, 5th, 10th, 23rd, 38th, 43rd, 47th, 52nd, and 59th Regiments, and the 1st Battalion of the Marines.
Each company had its own lieutenant, but the majority of the captains commanding them were volunteers attached to them at the last minute, drawn from all the regiments stationed in Boston.
This lack of familiarity between commander and company would cause problems during the battle.

The British began to awaken their troops at 9 pm on the night of April 18 and assembled them on the water's edge on the western end of Boston Common by 10 pm.
Colonel Smith was late in arriving, and there was no organized boat-loading operation, resulting in confusion at the staging area.
 The boats used were naval barges that were packed so tightly that there was no room to sit down.
When they disembarked near Phipps Farm in Cambridge, it was into waist-deep water at midnight.
After a lengthy halt to unload their gear, the regulars began their 17 miles (27 km) march to Concord at about 2 am.
During the wait they were provided with extra ammunition, cold salt pork, and hard sea biscuits.
They did not carry knapsacks, since they would not be encamped.
They carried their haversacks (food bags), canteens, muskets, and accoutrements, and marched off in wet, muddy shoes and soggy uniforms.
As they marched through Menotomy, sounds of the colonial alarms throughout the countryside caused the few officers who were aware of their mission to realize they had lost the element of surprise.

At about 3 am, Colonel Smith sent Major Pitcairn ahead with six companies of light infantry under orders to quick march to Concord.
At about 4 am Smith made the wise but belated decision to send a messenger back to Boston asking for reinforcements.
Around dusk, General Gage called a meeting of his senior officers at the Province House. He informed them that instructions 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 meeting adjourned around 8:30 pm, after which Earl Percy mingled with town folk on Boston Common. According to one account, the discussion among people there turned to the unusual movement of the British soldiers in the town. When Percy questioned one man further, the man replied, "Well, the regulars will miss their aim."
"What aim?" asked Percy. "Why, the cannon at Concord" was the reply. Upon hearing this, Percy quickly returned to Province House and relayed this information to General Gage. Stunned, Gage issued orders to prevent messengers from getting out of Boston, but these were too late to prevent Dawes and Revere from leaving.
The British regulars, around 700 infantry, were drawn from 11 of Gage's 13 occupying infantry regiments. Major Pitcairn commanded ten elite light infantry companies, and Lieutenant Colonel Benjamin Bernard commanded 11 grenadier companies, under the overall command of Lieutenant Colonel Smith.
Of the troops assigned to the expedition, 350 were from grenadier companies drawn from the 4th (King's Own), 5th, 10th, 18th (Royal Irish), 23rd, 38th, 43rd, 47th, 52nd and 59th Regiments of Foot, and the 1st Battalion of His Majesty's Marine Forces. Protecting the grenadier companies were about 320 light infantry from the 4th, 5th, 10th, 23rd, 38th, 43rd, 47th, 52nd, and 59th Regiments, and the 1st Battalion of the Marines. Each company had its own lieutenant, but the majority of the captains commanding them were volunteers attached to them at the last minute, drawn from all the regiments stationed in Boston. This lack of familiarity between commander and company would cause problems during the battle.
The British began to awaken their troops at 9 pm on the night of April 18 and assembled them on the water's edge on the western end of Boston Common by 10 pm. Colonel Smith was late in arriving, and there was no organized boat-loading operation, resulting in confusion at the staging area.  The boats used were naval barges that were packed so tightly that there was no room to sit down. When they disembarked near Phipps Farm in Cambridge, it was into waist-deep water at midnight. After a lengthy halt to unload their gear, the regulars began their 17 miles (27 km) march to Concord at about 2 am. During the wait they were provided with extra ammunition, cold salt pork, and hard sea biscuits. They did not carry knapsacks, since they would not be encamped. They carried their haversacks (food bags), canteens, muskets, and accoutrements, and marched off in wet, muddy shoes and soggy uniforms. As they marched through Menotomy, sounds of the colonial alarms throughout the countryside caused the few officers who were aware of their mission to realize they had lost the element of surprise.
At about 3 am, Colonel Smith sent Major Pitcairn ahead with six companies of light infantry under orders to quick march to Concord. At about 4 am Smith made the wise but belated decision to send a messenger back to Boston asking for reinforcements.
Battles of Lexington and Concord