(from the article `Garrison, William Lloyd`) ...from the American Colonization Society, which advocated the return of free blacks to Africa, to the principle of `immediate emancipation,` ...
Im·me'di·a·tism noun Immediateness. 
immediatism The quality of being immediate; immediateness, immediacy. The etymologicl development of media and medium.
a policy for the immediate abolition of slavery.