UNSC Meriwether Lewis
From Halopedia, the Halo wiki
UNSC Frigate. Captain Keyes served aboard this vessel, prior to 2552, and he was awarded the Medal of Honor for his efforts in defending the vessel against a Covenant attack with only a small security force.
In the Halo: Combat Evolved manual, this ship was classified as a Colony Ship for some reason. See: List of Inconsistencies in Halo
