The 19th century, is defined in the calendar of Earth as being from 1800 until 1899.
- The notation BCE ("Before Common Era") and CE ("Common Era") are alternative neutral notations for BC ("Before Christ") and AD ("anno Domini"), respectively.
- The Cardassian Union is established, with the Detapa Council being placed in authority over the Central Command and the Obsidian Order. (DS9: "Defiant")
- The Suliban homeworld in Sector 3641 becomes uninhabitable, forcing the species to become nomadic. Many settle in the Tandar sector. (ENT: "Broken Bow", "Detained")
- 1860 CE
- Abraham Lincoln wins the presidental election. (historical accounts)
- 1860s CE
- A group of Humans are abducted from Western North America by the Skagarans, an alien species, which wants to enslave its captives. The Humans are brought to a M-class planet inside the Delphic Expanse where they soon overwhelm their oppressors and start to rebuild their society by founding a Western-like colony. (ENT: "North Star")
- The date of the Humans' abduction is given indirectly as "40 years before the first flight of the Wright brothers," placing it around 1863.
- October 26, 1881 CE
- The infamous gunfight at the OK Corral is fought in Tombstone, Arizona on Earth. The event would forever define the violence and lawlessness which has become associated with the Ancient West. (TOS: "Spectre of the Gun")
- 1888-1891 CE
- The Redjac entity, incarnated as "Jack the Ripper" kills 17 women in London on Earth. (TOS: "Wolf in the Fold")
- August 13, 1893 CE
- A group of shapeshifters from Devidia II arrive on Earth, using a cholera epidemic as cover to kill Humans in order to steal their neural energy. Crew members from the USS Enterprise-D follow the Devidians back in time from the 24th century to stop them. (TNG: "Time's Arrow, Part II")
|18th century|| Timeline|