1855 was a year in the 19th century.
Events (but with Emmet Brown)
- Monday, October 22: Marty McFly arrives from 2025 to warn Emmet Brown, Clara was born 3 days later so Emmet has to be Clara's great grandpa.
- Wednesday, October 24: At the Clayton house, Martha Clayton asks Marty who's gonna be born 1 day later, Marty answers her the baby's name is Clara Clayton, Daniel asks him "How do you know about the baby?", then Marty tells them the truth like "I'm from the future so is Doc." Daniel and Martha was shocked also confused because they don't remember the way Emmet Brown come back to 1785 in the time machine because Emmet always lived with them and was always a great grandpa of Clara Clayton in the 19th century. Marty tells them his story about how he came back to 1855. Daniel and Martha was amazed, Marty tells them his idea on Clara's birthday in 1866, Marty will show Clara the time machine. So Daniel and Martha agreed. Marty was fuelling up the fusion generator when Emmet Brown came up to him, Emmet also agreed about Marty's plan while Marty was having a meeting with Clara's parents. Emmet tells Marty "I'll see you in 1866." Marty gets in the time machine and departs 1855 for 1866.
- Thursday, October 25: Clara Clayton is born to Daniel and Martha Clayton and Clara's great grandpa Emmet "Doc" Brown in New Jersey.
- If you fail to save Clara in the Back to the Future Part III video game, her Tombstone will incorrectly give the date of her death as 1855, rather than 1885. The same year will also be given if you lose as Marty against Buford Tannen and his gang.