How did St. Augustine's Fort Mose and Castillo de San Marcos play a vital role in the Underground Railroad? Objective Students will examine events and people in Florida history as it relates to the Underground Railroad. Background Read about Colonial African Americans in St. Augustine. Explore the NPS Underground Railroad collection. Preparation Explore these lessons and consider using before/after the Seeking Sanctuary lesson. The Role and Status of Africans in Spanish St. Augustine African Americans Settle in Fort Mose African Americans at Fort Mose Lesson Hook/Preview Watch Seeking Sanctuar Duration: 60 Minutes.