The Major Crimes Act is a U.S. federal law enacted in 1885 that grants federal jurisdiction over certain serious crimes committed by Native Americans on tribal lands. These crimes include offenses such as murder, manslaughter, and sexual assault. The Act was designed to address the limitations of state laws in prosecuting crimes in Indian Country, ensuring that serious offenses are handled appropriately. Under the Major Crimes Act, the federal government can prosecute these major crimes, which helps to maintain law and order in tribal communities. This law is significant in the context of tribal sovereignty and the relationship between Native American tribes and the federal government.