Chief Joseph had succeeded his father as head of their tribe in a stretch of land covering portions of what are today Oregon and Washington. There had been a spurious treaty bandied about which claimed the Nez Perce had ceded their ancestral lands to the whites. Chief Joseph tried to negotiate in good faith with Federal representatives, but Grant opened the land to white settlement without reference to those negotiations. Although an 1873 Federal order called for white settlers to be removed, Grant's action lead General O. O. Howard in 1877 to assemble a force of cavalry to remove the tribe to a reservation in Idaho--and he sent warning to that effect. Chief Joseph had resigned himself to the eventuality, but a band of about twenty young warriors attacked some white settlers, and the army began to hunt them down.
Chief Joseph then conducted a fourteen hundred mile (that's right 1400 miles) fighting retreat in which he used dedicated vanguards and rear guards, field fortifications, ambushes, skirmish lines--even William T. Sherman described his conduct of the retreat as scientific. He was trying to make it to Canada, but the army finally cornered him in Montana.
I highly recommend a reading of his life, he was a remarkable man. His fighting retreat was so famous in its time that the German Imperial General Staff included a study of it in their staff college course.
From where the sun stands today, i will fight no more forever.