After high-school, he joined the United States Army and served as a helicopter door-gunner in Vietnam.
He was awarded the Distinguished Flying Cross.
Once he returned to the U.S.
he became a Klansman, leading a maritime Louisiana KKK element against government help to Vietnamese immigrant fishermen.
He was also the leader of the Texas Emergency Reserve, a militia that was disbanded by the courts in 1982 as a result of a lawsuit filed under Texas anti-militia law by the Southern Poverty Law Center.
The lawsuit was brought by SPLC after the militia harassed Vietnamese fishermen during the 1981 fishing season.
Beam was using Camp Puller near Houston to train militia in 1980, including children as young as 8 years old, in armed guerrilla tactics; the camp was shut down after publicity led to protests, and parents complaining that they were not aware of the children's activities at the camp.
The Boy Scouts Council of Houston rejected a charter request from the troop at Camp Puller.
Videotape shown during the shrimper hearing had Beam saying, "We're going to assume authority in this country." He was later acquitted in a separate case of conspiring to overthrow the government.
He moved to Idaho afterwards.
He became active with Aryan Nations in the early 1980s.
He is considered to be the first important proponent of the strategy of leaderless resistance.
In recent years, Beam has maintained a significantly lower profile.
According to ADL/LEARN, he has been fighting against a government he views as "tyrannical and controlled by Jewish conspirators" for more than thirty years.
He first became engaged on the far right as a paramilitary Klansman, later with ties to Christian Identity groups.
He cites Thomas Jefferson in resistance to tyranny.
Beam refused the Aryan Nations' head Richard Girnt Butler's offer of leadership of the religious group in 1988 and chose to continue to work alone.
During the past twenty years, he has had limited influence except for rare postings on the internet.
His essay Leaderless Resistance has been translated into seven languages.