"Weather Underground, also called Weather Underground Organization, formerly Weatherman, militant group of young white Americans formed in 1969 that grew out of the anti-Vietnam War movement. The Weather Underground, originally known as Weatherman, evolved from the Third World Marxists, a faction within Students for a Democratic Society (SDS), the major national organization representing the burgeoning New Left in the late 1960s."
https://www.britannica.com/topic/Weathermen
"The Weather Underground was a radical left wing militant organization first active in 1969, founded on the Ann Arbor campus of the University of Michigan. Originally known as the Weathermen, the group was organized as a faction of Students for a Democratic Society (SDS) national leadership.[2] Officially known as the Weather Underground Organization (WUO) beginning in 1970, the group's express political goal was to create a revolutionary party to overthrow American imperialism"
https://en.wikipedia.org/wiki/Weather_Underground
"When SDS collapsed in 1969, the far-left Weather Underground (a splinter group of the Weathermen) stepped forward, inspired by communist ideologies and embracing violence and crime as a way to protest the Vietnam War, racism, and other left-wing aims."
https://www.globalsecurity.org/military/world/para/weatherman.htm
"The far-left, Weather Underground bombed the FBI headquarters, destroying 20 offices on three separate floors. The Weather Underground eventually claimed credit for 25 other bombings—including the U.S. Capitol, the Pentagon, the California Attorney General’s office, and a New York City police station."
https://www.objectivityistheobjective.com/post/unprecedented
"The Weather Underground Organization was the most famous American radical group committed to political violence in the late 1960s and early 1970s. Starting in the summer of 1970, FBI wanted posters featuring images of Bill Ayers, Bernardine Dohrn and a dozen others were hung prominently in every post office in the United States, and this continued for years."
https://time.com/4549409/the-weather-underground-bad-moon-rising/
"Barack Obama has said repeatedly that his association with ’60s radical Bill Ayers, a “radical, leftist, small-'c' communist," as he recently described himself, and one of the founders of the Weather Underground, an anti-war group during the Vietnam period, was entirely in passing. Ayers was just "a guy who lives in my neighborhood," said Obama, and "not somebody who I exchange ideas with on a regular basis.""
https://thehill.com/blogs/pundits-blog/presidential-campaign/32072-obama-and-bill-ayers-together-from-the-beginning
"The Weather Underground Organization—among the most notorious U.S. terrorist formations of the 1970s—has been the subject of documentaries, memoirs and countless academic studies."
https://www.politico.com/news/magazine/2020/05/03/us-history-first-women-terrorist-group-191037