an ancestor of mine was involved in a civil war in Argentina where British soldiers donned uniforms of, and posed as part of the Buenos Aires artillery troops inorder to operate new artillery pieces supplied from England. It was crucial to the ultimate success of the Buenos Aires side, because of the superior firepower and training provided by the British. The Brits backed Buenos Aires with this covert action because of commercial interests.
Then my ancestor suddenly appears next as part of the CSS Virginia's crew, and continues on to fight throughout the South. I've always wondered what happened to the surplus arms in the Buenos Aires campaign, and why a British soldier could move from that war into the middle of the Civil War.