Late 15th or Early 16th Century - Dekanawidah - "Great Peace Maker." Author of the Great Law of the Iroquois Confederacy that bound together five Indian Nations.
c.1767-1843 - Sequoyah - Cherokee silversmith. In 1821 completed his independent creation of a Cherokee syllabary, making reading & writing in Cherokee possible.
1786-1866 - Chief Seattle (Si'ahl) - Reputed for speech c.1854 advocating Native American rights & environmental values.
1811-1984 - Wendell Phillips - Abolitionist & advocate for Native Americans. Namesake of William Lloyd Garrison's son. WEB DuBois spoke about Phillips at his HS graduation. 
1840-1904 -
Chief Joseph - Nez Perce leader. Renowned as a humanitarian & peacemaker for his principled resistance to Indian removal. Said "I will fight no more forever."
1931-Alive - Billy Frank, Jr. - Environmental leader & advocate of Native American treaty rights. 
1992
1932-Alive - Dennis Banks - Cofounded American Indian Movement (AIM) in 1968. Depicted on peace mural in St. Paul, Minnesota (USA).
1939-2012 - Russell Means - Oglala Sioux activist. Leader of American Indian Movement (AIM). Helped lead uprising at Wounded Knee in 1973.
1945-1975 - Anna Mae Aquash - Mi'kmaq from Nova Scotia. Highest-ranking woman in American Indian Movement (AIM). Killed on Pine Ridge Indian Reservation. 
1946-2010 - Chief Jack Swamp - Mohawk. Founded Tree of Peace Society "to promote universal peace through the planting of trees throughout the world."
1947-Alive - Peter Wolf Toth - Sculptor. Has erected a large wooden sculpture of a Native American in every US state & many Canadian provinces.