This document provides brief biographies of 20 key figures from the American Civil War, including Abraham Lincoln, Robert E. Lee, Ulysses S. Grant, Stonewall Jackson, and Clara Barton. For each figure, it notes whether they represented the Union or Confederate side, and summarizes their role and importance before, during, or after the Civil War. The figures represented leaders from both sides who played military, political, social, or humanitarian roles in the pivotal events of the Civil War era in American history from the 1850s to the 1870s.