More here:
http://en.wikipedia.org/wiki/Warren_Wagon_Train_Raid
The ambush had been planned by a large band of Kiowa warriors under the leadership of Satanta, Big Tree, Satank, and Eagle Heart. Hidden in a thicket of scrub in the Salt Creek Prairie, they observed the slow approach of several wagons accompanied by 17 Buffalo soldiers of the 10th Cavalry Regiment, the black troopers. Relatively easy pickings, but no one moved.
The previous night, a shaman had prophesied that this small party would be followed by a larger one with more plunder for the taking. The braves were rewarded three hours later when 10 mule-drawn wagons filled with army corn and fodder trundled into view. The Kiowa attacked and quickly overwhelmed this convoy. Seven muleskinners were killed, while five managed to escape.
The warriors lost three of their own, but left with 41 mules heavily laden with supplies. It was well after dark before the white survivors reached the nearby Fort Richardson and told their harrowing tale to the very officer whose party had passed unharmed under the Kiowa guns, William Tecumseh Sherman.
He ordered the arrests of the Indian war chiefs, and had them sent to the fort. Satank was killed in the train as he tried to escape the column of United States soldiers. The rest were tried in the first Indian trial in history. Satanta and Big Tree were convicted of murder.
FUN FACT: Satanta was the inspiration for the character “Blue Duck” in the TV series “Lonesome Dove”.
I know of at least one earlier trial in Minnesota: Great Sioux Uprising
There may be other early Indian trials as well.