Question

What was discovered in 1870 in the Black Hills that brought many new settlers to the territory?

Answer 1

Actually in 1874 gold was discovered in the Black Hills and that caused a migration to the area.

Explanation:

In 1874 Lt. Colonal George Armstrong Custer was in charge of the Black Hills territory and was responsible for cavalry patrols to protect the Hills and to protect railroad surveyers as they were sacred ground to the Lakota Sioux tribes. Custer announced that gold had been discovered.