Final answer:
Simon Bolivar identified the need for a strong central government and Spanish American unity in the newly independent nations.
Step-by-step explanation:
The unifying factor that Simon Bolivar identified was his emphasis on the need for a strong central government and Spanish American unity in the newly independent nations. Unlike others who advocated for independence from Spain, Bolivar believed in a powerful executive and a republic system to ensure stability. He also envisioned a league of American nations to regularly meet and assist each other. Bolivar's efforts in liberating territories and his role in the Congress of Panama further exemplified his goal of creating and maintaining unity among Spanish American nations.