Complex sentence: She also organized the New York Travelers'Aid Society to protect migrants and immigrant women; she was a leader in the organization of the National Travelers' Aid Society, and she was a major force in the foundation of the international Travelers' Aid movement.
Split into simpler sentences: She also organized the New York Travelers'Aid Society to protect migrants and immigrant women. She was a leader in the organization of the National Travelers' Aid Society, and she was a major force in the foundation of the international Travelers' Aid movement.