Anderson, a member of the Tuscarora nation, was born on November 9, 1927, in Buffalo, New York. Called Mad Bear by his grandmother because of his temper, he grew up on the Tuscarora Indian Reservation, near Niagara Falls. As a young man, he enlisted in the U.S. Navy. After he returned from service, Anderson applied for a loan under the GI Bill to build a house on the reservation. When the loan was denied, Anderson's belief that he was discriminated against because of his race prompted him to become an activist for Native American rights.
In 1957, Anderson led Iroquois protests against state income taxes. The demonstrations culminated in a march to the Massena, New York, state courthouse, where several hundred protestors burned summonses for their unpaid taxes. The following year, Anderson became a key figure in the Tuscarora Reservoir Protest. After the Power Authority of the State of New York seized 1,383 acres of the Tuscarora Reservation to build a reservoir that would flood the land, Tuscarora men, women, and children joined forces to resist the taking of their land. Anderson and others blocked surveyors from entering the reservation and deflated workers' tires. When approximately 100 state troopers threatened to enter the reservation, the demonstrators laid in the road to block their trucks. Despite the efforts of the Tuscaroras, the U.S. Supreme Court ruled in Federal Power Commission v. Tuscarora Indian Nation (1960) that the taking of the land was legal, and the reservoir was eventually built.
In March 1959, Anderson aided in a revolt of Iroquois at the Six Nations Reserve in Brantford, Ontario. After the Iroquois declared their sovereignty, twelve Royal Canadian Mounted Police invaded the reservation's council house, but the Iroquois forced them to leave. That same month, Anderson attempted a citizen's arrest of Commissioner of Indian Affairs Glenn Emmons, whom some Native Americans, resentful of the federal termination policy, had accused of misconduct in office. Emmons avoided Anderson but later resigned.
After receiving an invitation from revolutionary leader Fidel Castro, Anderson led a delegation of Native Americans to Cuba in July 1959. Members of the Six Nations and the Miccosukee of Florida agreed to recognize the sovereignty of Cuba in exchange for Cuba's recognition of their own sovereignty. Indian sovereignty was an important issue for Anderson; he once stated that his main purpose in life was to help the Indian people regain sovereignty, rather than be absorbed by a society that he regarded as "sick."
Anderson founded the North American Indian Unity Caravan in 1967 to encourage the activism that was growing among Native Americans nationwide. Later that year, he delivered to Congress messages from 133 tribes that did not want their reservations to be terminated, which helped to defeat one of the final termination bills. Anderson toured the nation with his caravan for the following six years, but he paused to plan and participate in the Alcatraz Occupation in 1969. In 1975, he was the national director of the Indian Nationalist Movement of North America.
Anderson's work as a medicine man was featured in the book Rolling Thunder (1974) by Doug Boyd. In discussing his concept of good medicine, Anderson also articulates the philosophy behind his individual activism.
Boyd, Doug. 1994. Mad Bear: Spirit, Healing, and the Sacred in the Life of Native American Medicine Man. New York: Simon & Schuster.; Olson, James S., Mark Baxter, Jason M. Tetzloff, and Darren Pierson. 1997. Encyclopedia of American Indian Civil Rights. Westport, CT: Greenwood Press.; Roleff, Tamara, ed. 1998. Native American Rights. San Diego, CA: Greenhaven Press.