The U.S.S. Yorktown was an Excelsior-class vessel constructed some time before 2320. Origionally designed as a long-range star-mapping vessel, the Yorktown's hull was lined with extra sensor nodes.
By 2375, the Yorktown was under the command of Captain Alec Mitchel and was a member of the seventh fleet. It served with distiction during the Dominion War, where it was used mainly as a long-range sensor ship and scanning dampener.
The Yorktown was partnered with the USS Challenger briefly for an ill-fated mission behind enemy lines in early 2375. Though heavily damaged, the ship was able to escape. (novel: "Transcendence")
Shortly after, a Sovereign-class USS Yorktown was constructed. (RPG Star Trek: Roleplaying Game)
- It is unclear when the new Yorktown was built, but due to it's age, it was likely the earlier Yorktown was de-commisioned shortly after it's mission with the USS Challenger in 2375. Due to it's excellent war-record, the name may have been rushed back into service