American Civil War

The American Civil War was a conflict fought in the United States on Earth during the mid 19th century, between the northern, or Union, states and the former southern states - which had broken away and formed the Confederate States of America because of northern desires to end slavery in the southern states. The war ended in a northern victory, and brought about an eventual end to slavery and oppression on Earth. (VOY: "The Q and the Grey")

After Jonathan Archer witnessed a scene from the American Civil War as the timeline realigned itself after Archer's crew repaired the damage to the timeline. (ENT: "Storm Front, Part II")

Colonel Thaddius Riker fought in the Civil War for the Union. He was wounded during the course of the war, and was saved by another solider. Over 500 years later it was revealed that it was a member of the Q that saved the life of Thaddius. (VOY episode Death Wish)

During the war, the Union Army utilized observation balloons that were tendered at around six hundred feet high. (TOS: "The Savage Curtain")

The Q would later fight their own Civil War, and Q chose to represent the war by using an illusion of the American Civil War, in the hopes that the Voyager crew could comprehend the Continuum and the war they were fighting. (VOY: "The Q and the Grey")