Sitting Bull and Wounded Knee
Red Elk Woman, a member of the Sioux
In the 1500s and 1600s AD, Sioux people were still living around the Great Lakes (modern Minnesota); that's where they were in 1667 when they first met French fur traders. But by the 1700s the Sioux (you pronounce it SOO), along with the Cheyenne and the Arapaho, had left their home to live on the Great Plains instead, further west (in modern North and South Dakota and Minnesota).
The main reason that the Sioux moved to the Great Plains was that beginning in the early 1600s they were pushed out of the Great Lakes area by the Ojibwe and Chippewa people, who had been pushed out of their own land further east by European settlers. The Ojibwe and Chippewa had guns and used them to win battles against the Sioux. Another important factor was that about 1730 the Sioux got horses from the Cheyenne. By 1750 AD, the Sioux turned around and used their horses to push out the Cheyenne and the Kiowa and the Mandan, and hunt buffalo all over the Great Plains.
The Sioux supported the British against the Americans in the Revolutionary War in the late 1700s, but after the war the Sioux made a series of treaties with the Americans.
But by about 1850 AD people realized that this new system of hunting buffalo with horses also
had a bad side. Living so far north, where there were long cold snowy winters,
it was hard to find enough grass for the horses to eat during the winter.
Sioux people found that the horses could survive by eating the bark of cottonwood
trees. These trees grew in the valleys alongside rivers, so that's where
Sioux people took their horses in the winter.
But that's also where buffalo usually went to spend the winter, protected from the worst of the cold weather and snow. When people and horses were in the valleys, the buffalo were afraid to go there. Many buffalo died from the cold and snow, up on the high plains.
Between the unintended damage to the buffalo herds and the Sioux hunting the buffalo in the summer, by 1850 there were fewer and fewer buffalo around. Also, European people built the first railroad across the Great Plains at this time, which frightened the buffalo and made it hard for them to travel on their usual migration routes. The Sioux began to go hungry.
Sitting Bull (Tatanka Iotanka)
Now that the train was coming through, a lot of Europeans wanted to take over the Great Plains for themselves, to farm it. They could grow lots of corn there and ship it back to the East Coast cities on the trains. These Europeans realized that if they killed the rest of the buffalo, the Sioux would have to do whatever the European people wanted, in exchange for food.
So that's what they did. They killed almost all of the buffalo, just leaving them there to rot, and by the 1860s many Sioux had died and the rest were desperate. In 1862, Sioux warriors killed more than 800 Americans in Minnesota. After the Civil War ended in 1865, the United States was happy to send a lot of soldiers West to fight the Sioux (and the Navajo), and things began to get even worse. In 1868, the United States army signed a treaty with the Sioux that said that the United States would never let settlers move into the Black Hills. But when explorers found gold in the Black Hills four years later, the United States broke that treaty. There was a big battle over this - the Battle of the Little Big Horn - and the Sioux won, under their great chief Sitting Bull, killing many United States soldiers including General Custer. But winning the battle didn't help - there still weren't enough buffalo, and there were more and more United States soldiers.
In 1889, many of the Sioux turned to a new Christian idea of the Ghost Dance which they thought would protect them against their enemies. But all that happened was that United States soldiers came and killed Sitting Bull, and more Sioux were killed at Wounded Knee in 1890. By 1900, all Sioux people were living on reservations, under the control of the United States government.
A map of Sioux reservations about 2000 AD
During the 1900s, most Sioux lived on a large reservation covering about half of South Dakota and large parts of Nebraska, North Dakota, Wyoming, and Colorado. Many Sioux people still spoke their own language. Sioux people began to farm corn and raise cattle, and to work towards a tourist industry.