Complex sentence: Gotti was one of the most powerful and dangerous crime bosses in America, during his era and became widely known for his outspoken personality and flamboyant style, which gained him favor with much of the general public.
Split into simpler sentences: Gotti was one of the most powerful and dangerous crime bosses in America. During his era he became widely known for his outspoken personality and flamboyant style, which gained him favor with much of the general public.