Question

A score is equal to 20 years. Four

score and seven years ago is how the
speech began. Why did Lincoln refer to
that year?

Answer 1

Lincoln's address starts with “Four score and seven years ago.” A score is equal to 20 years, so he was referencing 87 years ago — 1776, when the Declaration of Independence was signed. The speech was made, then, seven score and seven years ago.

Answer 2

That was when the Declaration of Independence was sighned.