The fledgling United State government, after tasking themselves with exploring the vast and largely uncharted west, knew that their explorers (including Lewis and Clark) would encounter Native-American tribes. To that end, the explorers were sent with manufactured goods and symbols of their (supposedly) peaceful intentions. Among those were the 1803 Peace Flags that, along with peace medals and "commissions," written contracts that read that the United States "... will at all times be extended to his protection, so long as he dos acknowledge the authority of the same."
Some of these peace flags survived for many years, and some are still around today. This amazing historic photo shows two Chippewa-Cree men (Jim Gopher, also known as Loud Thunder on the left and Frenchman on the right) posing with noted Montana writer, politician and Native American advocate Frank LInderman on the right. The three men are holding a surviving 1803 Peace Flag. The photo was taken around 1933. In the background, a structure, possibly for the Sun Dance, is being constructed.
One interesting thing to note is the incredibly thin, even diaphonous material of the flag; the bodies of the men holding the flag can clearly be seen through the fabric.