What is the main idea of the gettysburg address?

Gettysburg Address is that the sacrifices of those who died on the battlefield of Gettysburg were made to preserve the principles of human equality and self-government as set forth in the Declaration of Independence.

Contributing factors  leading  to the harlem renaissance were the great migration of african americans to northern cities, which concentratedambitious  people in places where they could encourage each  other, and the first world war, which had created new industrial work opportunities for tens of thousands of people.

Nm-us history and geography