It's a strange post title but that's what they're called in the game. These are from Foundry (and one from somewhere else) and that's pretty much all the White Men you need to make a White Men's Column for Congo (but really one more). You can field an Explorer, a Retired Officer, a Reporter and/or a Scientist. And you can have a unit of four Soldiers and a unit of three Adventurers.
I also bought a zebra skin bag from Saddle-Goose which is perfect for Stress Tokens.