Final answer:
In Martin Luther King Jr.'s 'I Have a Dream' speech, the 'great American' referenced is Abraham Lincoln.
Step-by-step explanation:
In the “I Have a Dream” speech, the “great American” that Dr. Martin Luther King Jr. mentions at the start of the selection is Abraham Lincoln. King delivered this iconic speech from the steps of the Lincoln Memorial during the March on Washington for Jobs and Freedom on August 28, 1963. His speech highlighted the continued struggle for racial equality, emphasizing a vision of a society where individuals are judged by their character rather than the color of their skin. This aligns with the core values of American democracy and the creed that “all men are created equal,” a principle that Lincoln himself fought to uphold during his presidency.