Complex sentence: Silliman deemed slavery an "enormous evil" but also favored colonization of free African Americans in Liberia, serving as a board member of the Connecticut colonization society between 1828 and 1835.
Split into simpler sentences: Silliman deemed slavery an "enormous evil". He favored colonization of free African Americans in Liberia, serving as a board member of the Connecticut colonization society between 1828 and 1835.