Final answer:
Between 1900-1948, advocacy, legislation like the Indian Citizenship Act and Indian Reorganization Act, laid groundwork for Indian rights and self-governance.
Step-by-step explanation:
From 1900-1948, several events considerably shaped the development of Indian rights. Sarah Winnemucca and Charles Eastman advocated for Native American causes. The 1924 Indian Citizenship Act granted U.S. citizenship to all Native Americans born thereafter, with citizenship extended to all Native Americans by the Nationality Act of 1940.
The Indian Reorganization Act of 1934 ended the division of reservation land into allotments, allowing for self-governance, constitutional writing, and better management of lands and resources. This period also saw the establishment of the Indian National Congress, aiming for independence from colonial rule.