In the 19th century, over 250,000 Native Americans lived in the Great Plains -- between the Mississippi and Rocky Mountains. After the Civil War, however, the U.S. government began to increasingly focus on its territories in the West. Thousands of white settlers set out to conquer the region, while the native populations were attempting to remain on the land they had occupied for centuries. Skirmishes between the U.S. government and the Native American populations grew increasingly frequent and brutal.

In the Dakota Territory in April of 1868, the Treaty of Fort Laramie granted the Sioux nation ownership of the Black Hills, which were considered sacred grounds for the Sioux (also known as the Lakota) and Cheyenne Indians. There the Native Americans would live on the newly-created Great Sioux Reservation. But not all of them went. Although many did move, they frequently traveled seasonally to pursue better hunting opportunities.

In 1874, the U.S. government sent General George Custer on the Black Hills Expedition to choose a location for a new Army fort and to investigate the area's natural resources. The expedition's confirmation of gold in the region drew thousands of whites to the Black Hills, ultimately fueling tensions between the whites and the Native Americans, leading to the Great Sioux war of 1876 and Custer's Last Stand. 

June 8: 1874
Former Union Brigadier General George Custer receives written orders from General Alfred Terry to explore the Black Hills with his 7th Cavalry.

Custer spends the next few weeks at Fort Lincoln, Dakota Territory — southwest of Bismark -- preparing his expedition, which consists of 1,000 soldiers from his 7th Cavalry, 110 wagons, 70 Indian scouts, four reporters, and two gold miners.

July 2
The expedition sets out to the southwest toward the Heart River. The Cavalry's band plays Custer's favorite -- regimental battle song "Garry Owen."

Although Custer's wife Libbie had planned to come along, Custer tells her to stay at Fort Lincoln, citing the potential for Indian hostilities

July 16
The expedition crosses into Montana and begins to head directly south toward the Black Hills.

July 17
Still heading south, the group crosses the border into Wyoming Territory.

July 18
After traveling 290 miles, the expedition reaches the Belle Fourche River, a tributary of the Cheyenne River. As they approach the Black Hills, Custer and his men describe their first sight of the dramatic hills and the rolling, luscious landscape. "We have discovered a rich and beautiful country," Custer writes to Libbie.

July 22
Custer and the 7th Cavalry arrive in the Black Hills, three weeks and 330 miles from Fort Lincoln. They camp there two nights before beginning to explore the Black Hills. There are no signs of Native Americans, and the expedition begins to take on the air of a picnic. Custer goes on hunting expeditions with his closest men, and spends his spare time writing newspaper reports and magazine columns, which he submits under the penname "Nomad."

July 26
The expedition passes back into Dakota Territory.

Expedition photographer William Illingworth takes a picture of the wagon train from above Castle Creek Valley. The image becomes one of the most iconic photographs of the expedition.

July 27
Horatio N. Ross and William T. McKay, two miners tagging along on the expedition, begin to pan for gold. They hope to verify rumors of gold that circulated after previous expeditions to the region in the 1850s.

July 31
A group including Custer and Captain William Ludlow climb Harney Peak, the highest peak of the Black Hills. They do not return to camp until 1 a.m. the next morning.

August 1
In a valley below Harney Peak (on which Mount Rushmore will be carved in the 1930s) in the southern part of the Black Hills, the group sets up camp and remains for five days, the longest they will remain in any one place during the course of the expedition. From camp, they take day trips to explore the area.

August 2
The expedition discovers gold "right from the grass roots," as Custer reports to the New York Times. His account describes an abundance of gold in the Black Hills, but omits the fact that the Sioux legally hold the land.

Reporters embedded with the expedition will continue to file stories about the gold discovery, spreading headlines to dozens of newspapers across the country.

August 7
Custer shoots and kills a grizzly bear, which he claims is his greatest hunting achievement. He documents his western hunting excursions in order to boost his own reputation as a western conqueror and a fearless military leader.

August 10
The New York Tribune headlines the discovery of the “New Gold Country."

August 13
The expedition has left the Black Hills and begins the return trip to Fort Lincoln, heading north.

August 22
The New York Times publishes General Custer’s report in which he boasts about the wealth in the Black Hills. He describes gold "distributed throughout an extensive area within the Black Hills" as well as "rich pasturage" for livestock.

August 23
Now in the Northern Dakota Territory, the expedition turns east towards Bismark.

August 30
The expedition arrives back in Fort Lincoln.

An August headline announces gold fever in the Black Hills

Fall 1874
Lured by the promise of gold, miners across the country prepare for a journey to the Black Hills. An economic crisis in 1873 had left many U.S. citizens looking to the western frontier for quick wealth and a fresh start.

1875
By the fall, over 15,000 hopeful miners will have settled in the Dakota Territory. Dozens sneak in to the Black Hills, violating the Treaty of Fort Laramie; many are evacuated by the Army or killed by Indians.

The U.S. government offers to buy the Black Hills for $6 million, but Sioux leader Sitting Bull rejects the offer.

On November 3, President Ulysses S. Grant convenes with his cabinet and decides the Army will do nothing more to stop white settlers from entering the Black Hills.

In December the U.S. Commissioner on Indian Affairs orders all remaining Sioux living outside the reservation to move there by January 31, 1876. Despite the fact that this would be a near-impossible feat in the dead of winter, all who refuse will be considered hostile.

1876
The deadline passes and Great Sioux War begins between the U.S. and the Sioux and Cheyenne tribes. On June 25, 1876, Custer and the 7th Cavalry are overwhelmingly defeated at the Battle of Little Bighorn.

The following spring, in 1877, the Great Sioux War (also known as the Black Hills War) ended, with most Native Americans surrendering or fleeing to Canada.