The correct answer is:
Pennsylvania
The American Anti-Slavery Society (AASS; 1833–1870) was an abolitionist society founded by William Lloyd Garrison and Arthur Tappan. Founded on December of 1833 in Philadelphia, Pennsylvania, United States.
"The Society for the Relief of Free Negroes Unlawfully Held in Bondage, the first American society dedicated to the cause of abolition, is founded in Philadelphia on this day in 1775. The society changes its name to the Pennsylvania Society for Promoting the Abolition of Slavery and the Relief of Free Negroes Unlawfully Held in Bondage in 1784."