What is the theme in With Malice Toward None: The Life of Abraham Lincoln by Stephen B. Oates?

The biography expounds on Lincoln's ideas of freedom, and how they differed from other theories popular in his time. Lincoln took the Constitution very seriously, claiming it did not exclude black men from the pursuit of life, liberty, and happiness. Lincoln hated slavery from an early age, and continued to find it a flaw in the supposedly "free" republic—-by the people, of the people, for the people. Lincoln identified with the oppressed black man, and thought that every American should have the right to better circumstances. Lincoln himself felt he had been free to move from the son of a frontier farm to President of the United States, and thought personal freedoms and liberties essential to the Union.