Abraham Lincoln's presidency was extremely influential for modern American society. His leadership during the Civil War unified the nation and changed the way the United States viewed itself. His views on slavery and support of the 13th, 14th and 15th amendments paved the way for the movement toward racial equality that occurred in the 20th Century.
Lincoln's presidency and the Civil War had an enormous influence on the way Americans understood their own nationhood. Prior to the Civil War, the country thought of itself as a league of independent states. Although the power of the national government had grown and an American identity had started to develop, regional tensions were extremely high. These tensions eventually led to the Civil War. By responding promptly to southern secession, labeling the confederate states as being in rebellion and advocating non-vindictive reconstruction measures, Lincoln helped Americans see once and for all that the United States is a single nation and that no state may legitimately secede.
History.com relates Lincoln's life-long opposition to slavery and his reliance upon the Declaration of Independence as evidence of slavery's evil nature. Lincoln's rhetoric shaped Americans' modern understanding of the nation's founding documents. His words and work have contributed to a national opinion that regards complete racial equality as being part of the legacy of the nation's founding.