When did the Seminole finally rule themselves once they arrived in Indian Territory?

Answer 1

They always ruled themselves. However, it would help to define just what is a Seminole.

The term "Seminole" is a derivative of "cimarron" which means "wild men" in Spanish. The original Seminoles were given this name because they were Indians who had escaped from slavery in the British-controlled northern colonies. When they came to Florida, they were not called Seminoles as they were actually Creeks, Indians of Muskogee derivation. The Muskogean tribes comprised the Mississipian culture which were temple-mound builders. Among the Muskogean tribes were the Creeks, Hitichis and Yamasees of Georgia, the Apalachees of Florida, the Alabamas and Mobiles of Alabama, and the Choctaws, Chickasaws and Houmas of Mississippi.

The Origins of the Seminoles
The original Seminoles came to Florida because it was controlled by the Spanish, who had no interest in returning slaves to the British. They were mostly Lower Creeks who spoke the Mikasuki language, but other Indians, including Yuchis, Yamasees and Choctaws who had confronted Ponce de Leon and DeSoto, also joined the tribe in their trek to northern Florida from Georgia during the early 1700s.

By this time, many of the tribes in Florida, including the Tequestas, Calusas, Apalachees, Timucans and others, had been decimated by the Spanish presence, either in battles or by diseases such as smallpox. Out of an estimated 100,000 native Americans that occupied Florida during the 1500s, less than 50 survived.

In 1767, Upper Creeks from Alabama, who spoke the Muskogee language, settled in the Tampa area. Shortly after this, in 1771, the first recorded usage of the name "Seminole" to denote an actual tribe was recorded. In 1778, the Seminoles were joined by more Lower Creeks and a few Apalachees.

Much more can be found at the source link: