Prince of Thieves - Assassin's Creed III

Loot a convoy without killing any of its guards - 10

This can be done throughout the game. Convoys spawns throughout the Frontier.

Starting at the Fort, in Monmonth, in the Frontier. Run out of the fort entrance, and more than likely there will be convoy. Instead of killing the guards, select unarmed and continue to beat the guards up. Then loot from the chest in the back of the convoy trailer.

Prince of Thieves is a reference to Robin Hood: Prince of Thieve where Robin Hood stealing from the convoys stealthfully.

Prairie Schooner Wagon