I was attempting to find the actual source for this, which I could not find online, but in 1781 Hopocan/Captain Pipe of the Delaware gave a speech to the Colonel DePeyster, a British officer in the Ohio country tasked with recruiting natives to join the British.

The speech outlined Hopocan's reservations of allying with the British in the war. Hopocan viewed the war as a white man's war and feared that the British would sell them out after the war since the British and the Americans were the same people (He referred to the war as, "A quarrel amongst yourselves."). This speech came after Cornwallis' surrender at Yorktown, so that surely played into the concerns conveyed by Hopocan.

Hopefully that's what you were looking for.

Chief Joseph of the Nez Perce gave what is probably the most well-known oration given by any Pains Indian tribe when he surrendered to Gen. Nelson Miles in Montana during the denouement of the US army's tribal pacification campaigns (1877).

Quote: "Hear me, my chiefs: My heart is sick and sad. From where the sun now stands, I will fight no more forever."

For entire text, this source seems accurate: http://www.historyplace.com/speeches/joseph.htm

There were many famous Native American orators in the early history of the United States, and even before that in the colonial period.

One of these was Red Jacket, who gave a speech to the U.S Senate in a discussion of their cultural and religious differences, and of conversion of natives to Christianity. In the speech he connects the Christian God to the Iroquois conception of the Great Spirit and infers that the two, actually one in the same, gave different religious instructions to different peoples in a way that fit them best.

Brother, we do not wish to destroy your religion or take it from you. We only want to enjoy our own.

He was later given a medal of peace by George Washington.

You can read 'Religion of the White Man and the Red' here.