Final answer:
The Battle of Gettysburg occurred after the Battle of Chancellorsville and was a pivotal and costly encounter during the American Civil War.
Step-by-step explanation:
The Battle of Gettysburg occurred after the Battle of Chancellorsville. Gettysburg, which took place from July 1-3, 1863, in Adams County, Pennsylvania, was a significant engagement during the American Civil War. This battle was commanded by Confederate General Robert E. Lee and is known for being the costliest battle fought on North American soil. It is also marked as the turning point in the war, as the Confederate forces suffered substantial losses and henceforth lost momentum against the Union forces.