Final answer:
Option 1) Douglas's belief in the importance of his cause led to his desire to meet with Lincoln.
Step-by-step explanation:
The sentence that best states a central idea of 'Waiting for Mr. Lincoln' is option 1) Douglas's belief in the importance of his cause led to his desire to meet with Lincoln. This sentence highlights the main character's motivation and his belief in the significance of his cause, which drives him to seek a meeting with Lincoln. It suggests that Douglas's conviction and dedication play a crucial role in the story.