Osage chauffeured cars
In the early 20th century, the members of the Osage Nation became the richest people per capita in the world, after oil was discovered under their reservation, in Northeast Oklahoma. Then they began to be mysteriously murdered off. The case became one of the FBI's first major homicide investigations.

In telling this largely forgotten history in my new book, "Killers of the Flower Moon: The Osage Murders and the Birth of the FBI," I drew on many archival and contemporary photographs to help document what happened. Here are some of the most powerful images.

In the early 1870s, the Osage had been driven from their lands in Kansas onto a rocky, presumably worthless reservation in northeastern Oklahoma.

An early Osage camp on the reservation:
Osage reservation
This land, it turned out, was sitting above some of the largest oil deposits then in the United States. To extract that oil, prospectors had to pay the two thousand or so Osage for leases and royalties. In 1923, these Osage received collectively what would be worth today more than $400 million. Many of the Osage lived in mansions and had chauffeured cars.
Osage chauffeured cars
Then the Osage began to die under mysterious circumstances. The family of Mollie Burkhart, an Osage woman, became a prime target.
Mollie Burkhart, an Osage woman
In the spring of 1921, Mollie's older sister, Anna, disappeared.

A week later, Anna was found in this ravine, shot in the back of the head.
Anna  Burkhart  found in ravine, shot in the back of the head.
Less than two months after Anna's murder, Mollie's mother, Lizzie, died. Evidence would later suggest that she had been poisoned.

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