What caused the second fort laramie treaty?

The Second Fort Laramie Treaty, signed in 1868, was primarily caused by the increasing tensions between the U.S. government and Native American tribes due to westward expansion, particularly following the discovery of gold in the Black Hills. The U.S. sought to establish peace and stability in the region, which was crucial for the construction of the transcontinental railroad. Additionally, the treaty aimed to protect Native American lands from encroachment and provide for their welfare in exchange for their cooperation. Ultimately, the treaty was an effort to resolve conflicts and prevent violence as settlers moved into tribal territories.