Casualties
The official British Army casualty return, signed by Lieutenant Colonel John Harvey, the Deputy Adjutant-General, gave 7 killed and 33 wounded for the 2nd Battalion, Royal Marines, 8 killed and 17 wounded for the Regiment de Watteville and 9 wounded for the Glengarry Light Infantry. The separate Royal Navy casualty return for the engagement, signed by Yeo, gave 3 killed and 10 wounded for the Navy and 6 killed and 27 wounded for the Royal Marines. This would give a grand total of either 18 killed and 69 wounded or 17 killed and 63 wounded, depending upon whether the Army or Navy casualty list is correct for the Royal Marines' losses. Captain Mulcaster was seriously wounded by grapeshot, losing a leg.
The American losses are hard to determine. Mitchell's casualty return, which apparently included the U.S. regular troops only, stated the loss as 6 killed, 38 wounded and 25 missing. General Drummond's report of the engagement to Sir George Prevost stated that the British captured "about 60 men, half of them severely wounded". Another British report, however, said that only 25 American soldiers and 1 "civilian" (possibly a militiaman) were captured. Still another British account said that 1 officer and 20 enlisted men of the Americans were found dead on the battlefield.
Read more about this topic: Battle Of Fort Oswego (1814)