Abraham Lincoln, the 16th president of the United States, led the nation through the Civil War, preserving the Union and abolishing slavery. Rising from poverty, he became a prominent lawyer and politician, ultimately elected president in 1860 amidst tensions over slavery. Lincoln's legacy includes the Emancipation Proclamation, promoting the Thirteenth Amendment, and being recognized as a martyr for his leadership and reconciliation efforts, ranking him among the greatest presidents in American history.