Throughout the 19th century, the people of the Osage Nation, like many other Native American groups, were forced to relocate from their traditional tribal lands to “Indian Territory,” land set aside as reservations by the federal government. The Osage shared this unincorporated territory with other tribes, including the Cherokee, Seminole, Choctaw, Chickasaw, and Creek.

In the late 19th century, Indian Territory became part of the new State of Oklahoma and tribal lands were gradually reduced in size, but on some of the lands assigned to the Osage, which became Osage County, something very dramatic happened: oil was discovered. At first, that didn’t seem too important - in the 1880s, oil was useful but wasn’t the source of wealth it would later become. However, the rise of the automobile changed everything. In 1900, there were only around 4,000 automobiles registered in America, but by 1908, there were over 60,000, and by the early 1920s, there were over 15 million. Every single one needed fuel and lubricants that came from oil, and as a result, “black gold” became one of the most valuable commodities on Earth.

For the Osage, the explosion in demand for oil brought unimaginable wealth. In 1923 alone, the Osage Nation received over $30 million in oil revenue, worth over $400 million in current value, and individual members of the tribe became extremely wealthy. Unscrupulous people began to plot how they could get their hands on some of this wealth.
Then the murders began.

In the early 1920s, members of the Osage Nation and others began to turn up dead, and in many cases, the proceeds of oil revenue owned by these people passed to white “Guardians” appointed by the federal government. By 1925, at least 24 Osage had died in unexplained circumstances, and some accounts suggest that the actual number may have been over 100. Local law enforcement seemed unable (or perhaps unwilling) to investigate effectively, and it was left to a small bureau in Washington to undertake their first homicide investigation under the leadership of a dynamic and ambitious young lawyer named J. Edgar Hoover. As a result, the horrifying true story of the Osage County murders became one of the first assignments for the federal agency that would later become the FBI.