Complex sentence: His enemies included fellow abolitionists who disagreed with his tactics, including his participation in the well-publicized Darg case of 1838 involving a Virginia slaveholder named John P. Darg and one of his slaves, Thomas Hughes.
Split into simpler sentences: His enemies included fellow abolitionists who disagreed with his tactics. He was criticized for his role in the well-publicized Darg case of 1838 involving a Virginia slaveholder named John P. Darg and his slave, Thomas Hughes.