Complex sentence: Jack Foner taught history in 1935 at Baruch College (then called the downtown branch of the City College of New York), and actively supported the Spanish Republic against fascism, and stood for the rights of African Americans.
Split into simpler sentences: Jack Foner taught history in 1935 at Baruch College (then called the downtown branch of the City College of New York). He actively supported the Spanish Republic against fascism, and stood for the rights of African Americans.