Chief Joseph seems tired. He had enough and for sure, all the tragedy that he has seen and the fact that he doesn't know even if his sons are alive is deeply depressing, but it is the last phrase that gives meaning to the whole letter, since he decides that he is never going to fight again.
That is why the answer is From where the sun now stands I will continue to fight.
This phrase would make the letter more hopeful and it would feel like the words of a brave man that will fight no matter what he faces.
Developed in the 1830s and 1840s by Samuel Morse (1791-1872) and other inventors, the telegraph revolutionized long-distance communication. It worked by transmitting electrical signals over a wire laid between stations.
The Gulf of Tonkin Resolution authorized President Lyndon Johnson to “take all necessary measures to repel any armed attack against the forces of the United States and to prevent further aggression” by the communist government of North Vietnam.