The Yanks to the rescue. Or not.
There were a number of Americans, well armed and organised in various brigades. The most important of these, at least for the purposes of our story, was the wonderfully named Independent Californian Rangers' Revolver Brigade, commanded by an actual former military officer, albeit only a tiny bantam-like 21 year old lieutenant, James McGill. McGill's real name was McGillicuddy. He was born in the USA, but was largely raised in Ireland. His parents moved back to the US in 1848 and sent him, apparently at the age of about 15 and with a brother, the age of whom is unknown, to the West Point Military School, where he trained to be a US army officer. He saw no action.