Another form of currency: livestock.  This has roots in our agricultural based culture, but was a also a major currency for Native Americans.  Counting coup on an enemy as well as stealing his horse, was considered the most honorable sign of bravery and accomplishment.  To take his horses from underneath his nose, a huge insult and achievement.  The number of horses one owned symbolized wealth.  A herd of horses was often necessary in order to obtain a bride.

In recently reading an account about Crazy Horse, it was mentioned that once Native Americans voluntarily moved to the reservations, in order to control them, the government took all but one of their horses.  Image what that did for morale… going along with the requirements of the government, and having them confiscate your currency!  Not a huge motivation for compliance…