What is lincoln defending in the speech of gettysburg address?

In the speech written in the Gettysburg Address Lincoln was defending civil rights. He was equally defending freedom and dedicated his speech to all the soldiers who lost their lives defending freedom and their beliefs. Lincoln also mentioned fundamental American rights, such as the United States being a country "by the people and for the people." His speech is one of the best known speeches in American history and marked one of the end points of the Civil War and the defeat of the Confederate Army by the Union Army.

  the domino theory states that  if one country in a region came under the influence of communism, then the surrounding countries would follow in a  domino  effect.