Below is a transcript of the letter;
Where'd we come from? Us Orcs? That's what I want to know? Tortured Elves, pulled out of a vat by some sort of dark sorcery. Orthog says that the first Dark Lord Morgoth mated with some Elf Queen in the forest. It's all hogwash if you ask me.
Stories made up to keep us marchin', keep us fightin' their dirty wars. I reckon we were here before the lot of 'em and we'll still be here when them and their stinkin' wars are long gone.