Lolita Lebrón, who blazed her way to notoriety with a Luger pistol and patriotic shouts as she led three other Puerto Rican nationalists in an attack on the United States House of Representatives on March 1, 1954, died Sunday in San Juan, P.R. She was 90.

The cause was heart and lung failure, said Linda Alonso Lebrón, her niece.

In the attack in the Capitol, Ms. Lebrón and the other assailants fired from a spectator’s gallery just above the House floor, raining as many as 30 bullets into a chaotic chamber and wounding five congressmen.

Ms. Lebrón was imprisoned for 25 years and widely condemned as a terrorist, although proponents of Puerto Rican independence hailed her and her associates as revolutionary heroes. She ascended into a leftist pantheon with figures like Che Guevara, becoming the subject of books and artwork.

Ms. Lebrón always said she remained proud of the shooting, which came two years after Puerto Rico, formerly a territory of the United States, had become a commonwealth. She dismissed that status as only more colonization and demanded complete independence. On the day of the shooting, she said she had fully expected to give up her life.