Final answer:
William Bradford's experiences founding Plymouth Colony and his reflections on overcoming difficulties resonate with the themes in Kennedy's speech, inspiring courage and a pioneering spirit in the face of challenges to progress.
Step-by-step explanation:
The details related to William Bradford support the main idea of President Kennedy's speech by emphasizing the courage and determination required to overcome great difficulties in the pursuit of honorable actions and the establishment of new enterprises. Bradford's experiences as the governor of the Plymouth Colony illustrate the challenges faced by the Pilgrims as they founded a new settlement in the harsh conditions of New England. Their signing of the Mayflower Compact and subsequent interactions with the native population laid the groundwork for democratic principles and self-governance in the Americas. Similarly, Kennedy's call for Americans to be 'new pioneers' suggests a continuation of that spirit of adventure and willingness to tackle formidable challenges for the greater good. These historical events are evoked to inspire a modern audience to act with the same bravery and commitment as their forebears.