Opening skirmish

At about midday on the 12th, Stricker heard the British had halted while the soldiers had a meal, and some sailors attached to Ross's force plundered nearby farms. He decided it would be better to provoke a fight rather than wait for a possible British night attack. At 1:00 pm, he sent Major Richard Heath with 250 men and one cannon to draw the British to Stricker's main force.^[11]

Heath advanced down the road and soon began to engage the British pickets. When Ross heard the fighting, he quickly left his meal and ran to the scene.^[11] His men attempted to drive out the concealed American riflemen. Rear Admiral George Cockburn, second in command of the Royal Navy's American Station who usually accompanied Ross, was cautious about advancing without more support and Ross agreed that he would leave and bring back the main army.^[11] However, Ross never got the chance, as an American rifleman shot him in the chest.^[11] Mortally wounded, Ross turned command over to Colonel Arthur Brooke and died soon after.^[11]

Main battle

Brooke reorganized the British troops and prepared to assault the American positions at 3:00 pm.^[11] He decided to use his three cannon to cover an attempt by his 4th Regiment to get around the American flank, while two more regiments and the naval brigade would assault the American center.^[11] The British frontal assault took heavy casualties as the American riflemen fired into the British ranks, and lacking canister the Americans loaded their cannon with broken locks, nails and horseshoes, firing scrap metal at the British advance.^[11] Nevertheless, the British 4th Regiment managed to outflank the American positions and sent many of the American regiments fleeing. Stricker was able to conduct an organized retreat, with his men firing volleys as they continued to fall back. This proved effective, killing one of the British commanders and leaving some units lost among woods and swampy creeks, with others in confusion.^[11]

Not all the militia regiments performed with equal distinction. The 51st Regiment and some men of the 39th broke and ran under fire. Robert Henry Goldsborough, US Senator and serving as a Major in the militia, reflected his feelings on the conduct of the militia units and the battle in general a week later, stating that:

The affair at Baltimore was...as little glorious to our arms as that at Bladensburg]]. Our militia were completely defeated routed.^[13]

Goldsborough's account of the battle is distinctly more critical and pessimistic than those of Smith and Stricker, and arguably has a greater basis in reality. For example, Smith initially stated the British had near double the numbers they actually had, which is not the first example of exaggeration on the part of the American commanders involved with the affair at Baltimore.^[14] However, the 5th and 27th held their ground and retreated in good order, having inflicted significant casualties on the enemy.^[15] Only one American gun was lost.^{[citation needed]}

Corporal John McHenry of the 5th Regiment wrote of the battle:

Our Regiment, the 5th, carried off the praise from the other regiments engaged, so did the company to which I have the honor to belong cover itself with glory. When compared to the [other] Regiments we were the last that left the ground... had our Regiment not retreated at the time it did we should have been cut off in two minutes.^[15]

Brooke did not follow the retreating Americans. He had advanced to within a mile of the main American position, but he had suffered heavier casualties than the Americans. As it was getting dark, he chose to wait until Fort McHenry was expected to be neutralized,^[16] while Stricker withdrew to Baltimore's main defences.^{[citation needed]}

Casualties

The official British Army casualty report, signed by Major Henry Debbeig, gives 39 killed and 251 wounded. Of these, 28 killed and 217 wounded belonged to the British Army; 6 killed and 20 wounded belonged to the 2nd and 3rd Battalions of the Royal Marines; 4 killed and 11 wounded belonged to the contingents of Royal Marines detached from Cockburn's fleet; and 1 killed (Elias Taylor) and 3 wounded belonged to the Royal Marine Artillery.^[4] As was normal, the Royal Navy submitted a separate casualty return for the engagement, signed by Rear-Admiral Cockburn, which gives 4 sailors killed and 28 wounded but contradicts the British Army casualty report by giving 3 killed (1 and 2 from HMS Madagascar and HMS Ramillies respectively) and 15 wounded for the Royal Marines detached from the ships of the Naval fleet.^[17] A subsequent casualty return from Cochrane to the Admiralty, dated 22 September 1814, gives 6 sailors killed, 1 missing and 32 wounded, with Royal Marines casualties of 1 killed and 16 wounded.^[18] The total British losses, as officially reported, were either 43 killed and 279 wounded or 42 killed and 283 wounded, depending on which of the two casualty returns was accurate. Historian Franklin R. Mullaly gives still another version of the British casualties, 46 killed and 295 wounded, despite using these same sources.^[19][20][21] The American loss was 24 killed, 139 wounded and 50 taken prisoner.