•Why it earns a slot
The proof that length and weight are different axes. The shortest entry in this archive took two minutes to deliver and holds more than most books.
In roughly 270 words, Lincoln reframed the Civil War as a test of whether a nation conceived in liberty and dedicated to human equality can endure, and turned a cemetery dedication into a charge to the living: finish the work, so that government of, by, and for the people shall not perish.
This distillation is written from the freely available original, which is always the better read when you have the time: loc.gov.