Which person's action was most closely associated with the abolitionist movement?

The person's action that was most closely associated with the abolitionist movement is William Lloyd Garrison's publication of the Liberator.

Anti-abolitionist handbills sometimes led to violent clashes between pro-slavery an anti-slavery factions. For the entire generation of people that grew up in the years that led to the Civil War, William Lloyd Garrison was the voice of Abolitionism.