He was 23 years old, and a sergeant in the 23rd Regiment (later The Royal Welch Fusiliers), British Army during the Crimean War when the following deed took place for which he was awarded the VC.
On 20 September 1854, in the Crimea, at the Battle of the Alma, Sergeant O'Connor was advancing between two officers, carrying the Colour, when one of them was mortally wounded. Sergeant O'Connor was also shot at the same time, but recovering himself, he snatched up the Colour from the ground and continued to carry it until the end of the action, although urged to retire to the rear on account of his wounds. He also acted with great gallantry at the assault on the Redan (8 September 1855) where he was shot through both thighs.
First man of the Army to perform an action subsequently rewarded with the VC. He later achieved the rank of Major General. He died Charges Street, London 1 February 1915. Grave/Memorial: St Mary's (RC) cemetery Kensal Rise, London.
His Victoria Cross is displayed at the Royal Welch Fusiliers Museum (Caernarfon Castle, Gwynedd, Wales).
spent his 18th birthday in a prison cell.