Who does Dr. King refer to by the epithet "Great American"?

In his I Have a
Dream speech, Dr. Martin Luther King Jr. refers to Abraham Lincoln as the great
American.

Five score years ago, a great American, in whose
symbolic shadow we stand today, signed the Emancipation Proclamation.

The Emancipation Proclamation, signed by President Lincoln during
the Civil War in 1863 (100 years, or five score years, before Kings speech in 1963), freed the
slaves in the South. (It was not until the Thirteenth Amendment that slavery would formally be
abolished throughout all of the United States.) But King argues that Lincolns words have not
been fulfilled.

One hundred years later, the Negro still
is not free.

Standing on the steps of the Lincoln
Memorial, in both the literal and symbolic shadow of Lincoln, King makes many allusions to
Lincolnnot only to the Emancipation Proclamation but also to the Gettysburg Address. Kings
phrase five score years ago recalls Lincolns phrase,

Fourscore and seven years ago our fathers brought forth, on this continent, a new
nation, conceived in liberty and dedicated to the proposition that all men are created
equal.

Lincoln wanted to ground his words in history by
connecting his words and actions to the Founding Fathers, who established this nation with the
Declaration of Independence, which emphasizes that all men are created equal. King also makes a
similar connection to history, making a timeline that starts with the Declaration of
Independence in 1776 and continues to the great American, Abraham Lincoln, signing the
Emancipation Proclamation in 1863. King then extends the timeline to his present moment, the
fierce urgency of now, August 28, 1963. On that day, King exhorted the crowd and all of his
fellow Americans to keep working toward the dream promised since the very beginning of the
country, a dream that Lincoln and all great Americans work toward, a dream in which every
person, no matter the color of his or her skin, will finally be free.

This will be the day when all of Gods children will be able to sing
with a new meaning, My country, €˜tis of thee, sweet land of liberty, of thee I sing. Land
where my fathers died, land of the pilgrims pride, from every mountainside, let freedom
ring.