In 1993, she quit her job as a lawyer in Indianapolis, Indiana to start the American Justice Federation, a non-profit group that promoted pro-gun causes through a shortwave radio program, a computer bulletin board system, and sales of its newsletter and videos. Thompson was opposed to the Bill Clinton presidency. In 1994, in a letter to congressional leaders, former Rep.
William Dannemeyer listed 24 people with some connection to Clinton who had died "under other than natural circumstances" and called for hearings on the matter. This list was mostly compiled by Thompson. The videotape was distributed widely and for a short period after its release she was a regular guest on talk radio shows.
Thompson also claimed that three BATF agents, whom she alleges were killed by friendly fire during the siege, were all former bodyguards of then-President Clinton and that the friendly fire was actually an assassination ordered by Clinton. In 1994, Thompson produced Waco II, the Big Lie Continues, in which she offered rebuttals to those who were critical of her first film. She made a third film in 1994, America Under Siege accusing the government of using "black helicopters" against patriots, and the Federal Emergency Management Agency of establishing concentration camps, facilities she claimed were to prevent patriots from interfering with plans to establish a "New World Order".
The supposed FEMA Camp was in reality the Beech Grove Shops, an Amtrak repair facility in Beech Grove, Indiana. In 1994 Thompson declared herself "Acting Adjutant General" of the "Unorganized Militia of the United States" and announced plans for an armed march on Washington, D.C. in September of that year. She declared that militiamen would arrest and try for treason in "Citizen's Courts" those Congressional representatives not living up to their oath of office.
The proposed march was almost immediately denounced by groups on the right wing, including the John Birch Society, and Thompson subsequently cancelled the march. Later, she was arrested for blocking a Presidential motorcade in Indianapolis. She carried one weapon concealed and also had one in her purse.
Both guns were legal and no charges were filed. Thompson died in St. Petersburg, Florida on May 10, 2009 after overdosing on medication given to treat complications from a gastric bypass surgery performed twelve years earlier.