Final answer:
Jane Addams and Jacob Riis were known for their efforts to aid the urban poor through initiatives such as founding settlement houses and exposing the conditions in tenements.
Step-by-step explanation:
Jane Addams and Jacob Riis were most notable for their efforts to aid the urban poor. Jane Addams founded Chicago's Hull House in 1889, providing social services, education, and health care to working-class women and their children. Jacob Riis, through his book 'How the Other Half Lives', exposed the abject poverty in tenement slums and contributed to the passing of laws to improve tenements in New York.