September 4 is the anniversary of the Surrender of Geronimo in 1886. This marked the end of meaningful resistance to the colonisers in the US. Geronimo had lost his family to white settlers when he was 30, and had spent the next 27 years of his life fighting for the freedom of his people.
By this time, the Indian Removal Act was in full swing. The US needed to clear out all the natives in order to make room for white settlers. So they moved all the natives into small chunks of less desirable land. The traditional way of life was impossible, and the natives were forced to try to take up farming. Farming with no experience or history of doing so is challenging enough on its own. But on barren land, it’s even worse.
Geronimo found being imprisoned on the reservation to be unacceptable, and he escaped with a band of warriors. The US army caught him and dragged him back. This repeated more than once. The last time was on September 4, 1886.
Geronimo was forced to live the last years of his life in squalor on the reservation, and he remains there to this day. 22% of native peoples live in squalor to this day.