Complex sentence: With the north becoming increasingly against the idea of fugitive slave catchers they adopted "anti-southern" views, several northern states passed new personal liberty laws in defiance of the South's efforts to have slaves captured and returned.
Split into simpler sentences: With the north becoming increasingly against the idea of fugitive slave catchers they adopted "anti-southern" views. Several northern states passed new personal liberty laws in defiance of the South's efforts to have slaves captured and returned.