"Using Cheyenne/Lakota methods, you are able to mount your cavalry more quickly, which trains them faster."—In-game description
Cheyenne Horse Trading (Lakota Horse Trading prior to The WarChiefs) is a technology in Age of Empires III that can be researched at a Trading Post built on a Cheyenne (Lakota before The WarChiefs) settlement. Once researched, it reduces the training time of cavalry and light infantry by 25%. In The Asian Dynasties, this technology also reduces the training time of Forbidden Army by 25%, as well as Standard Army, Mongolian Army, Ming Army, and Imperial Army by 12%.
Cheyenne/Lakota Horse Trading is a must have in Treaty or Deathmatch games, especially for civilizations which possess unique cavalry units such as the Spanish Lancer, French Cuirassier, and Russian Oprichnik.