In addition to making speeches and printing newspapers, many abolitionists wrote petitions asking congress to outlaw slavery. organized armed rebellions in southern states. bought enslaved people in order to set them free. taught young african american children in schools.

I believe the answer is wrote petitions asking Congress to outlaw slavery.
For example, Benjamin Franklin is one of the most prominent abolitionist figures in our country, 
In 1789, he wrote several essays that support the elimination of slavery and send a petition to Congress to end slaves trade as his last public action.