"i really can't understand this sentence because it is so ambiguous. could you revise and make it clearer? " which words in the sentence give the best clues to the meaning of ambiguous?

It is saying to give the definition of the word ambiguous, if that didnt help then you need to ask more clearer.

answer: military leaders, supporters of the confederacy and supporters of the union.

explanation:

on november 19, 1863, the speech delivered by president abraham lincoln, known as 'gettysburg address', was intended for politicians, military officials, notable citizens as well as general public, and members of the press who had gathered for the ceremony held in gettysburg, pennsylvania. this ceremony was being celebrated since, in that same year, the battle of gettysburg took place in rural pennsylvania, leaving thousands of men, both union and confederate, killed. lincoln argued about equality within the nation, and the purpose of the war being a "new birth of freedom."on the other hand, there is no relation between lincoln's gettysburg address and his son.