There is many tribes.
The Sioux are broken down into 5 main nations. Lakota, Dakota, Nakota, Saponi, and Catawba. Among these are many tribes.
The Sioux makes up about 1/4th of all tribes in North America.
Your question is in the present tense, so figures are fairly accurate:
Sisseton...............5,460
Wahpeton............4,100
Wahpekute...........2,050
Mdewakanton.......1,550
Yankton.................2,000
Yanktonai..............4,900
Brule....................10,000
Oglala...................12,000
Minneconjou, Sans Arc, Two Kettle and Blackfoot Sioux.......3,000
Historically, at first contact with explorers the Eastern (Dakota) tribes numbered around 4,500 people; the central (Nakota) tribes around 11,500 people and the western (Lakota) tribes numbered around 10,000 people.
two of the chiefs leading the Sioux were sitting bull and Crazy horse.as many as 2,000 Indian warriors quickly surrounded Custer and his men
Yes, he was one of the first major Indian chiefs.
A Sioux chief would be the leader of a tribe among the many tribes of the great Sioux nation. There was many chiefs among the Sioux nations across North America.
Red Cloud.
Sitting Bull and Crazy Horse. Sitting Bull was elderly and did not fight in the battle, but he was widely respected among the Sioux, and his vision of a Sioux victory was instrumental in rallying them to fight.
Two
The Quapaw were a division of a larger group known as the Dhegiha Sioux many years ago. I got this information directly form the Quapaw tribe website.
Sitting Bull, Morning Star, Spotted Tail, Crazy Horse were all chiefs of various Sioux tribes.
the Lakotas are an American indian tribe, better known as the sioux
The Dakota Sioux have several Indian reservations: Pine Ridge, Rosebud, Brule, etc.
Cheilftan Dances withsqurielle
Probably the easiest way is to visit one of the Sioux reservations.