What’s Lincoln’s main argument

Answer: To provide you with a detailed explanation, I'll need more context regarding which of Abraham Lincoln's speeches or writings you're referring to. However, I'll assume you're asking about Lincoln's main argument in the Gettysburg Address, one of his most famous speeches.

In the Gettysburg Address, Lincoln's main argument is centered around the idea of national unity and the importance of continuing the fight for the principles of liberty and equality upon which the United States was founded. He emphasizes the sacrifice of those who fought in the Battle of Gettysburg during the Civil War and argues that the living must dedicate themselves to preserving the nation so that "government of the people, by the people, for the people, shall not perish from the earth."

Lincoln's speech is a call to honor the dead by committing to the cause for which they gave their lives—the cause of a united country and the continuation of democracy. While the speech is brief, it is poignant in its message that the civil war was not just a fight to preserve the Union, but also a struggle to ensure the survival of the principles of human equality enshrined in the Declaration of Independence.