Why does lincoln begin his eulogy to the soldiers buried at gettysburg with a reference to four score and seven years ago what significant event happened in america 87 years before 1863?

Lincoln’s main objective in his Gettysburg Address was to unite the nation again and regain the purpose of being a strong country. Because of that, he began his eulogy with the phrase “four score and seven years ago” which referenced to the signing of the Declaration of Independence, the major American symbol of Union and strong country.

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

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