Complex sentence: The notable suffragist and social worker Jane Addams gave a seconding speech for Roosevelt's nomination, but Roosevelt insisted on excluding black Republicans from the South (whom he regarded as a corrupt and ineffective element).
Split into simpler sentences: The notable suffragist and social worker Jane Addams gave a seconding speech for Roosevelt's nomination. However, Roosevelt insisted on excluding black Republicans from the South (whom he regarded as a corrupt and ineffective element).