History and specifications
It was the first of the Declaration-class, intended specifically to travel the main Federation space routes between major member worlds, such as Earth–Alpha Centauri. It began service on reference stardate 1/23, near the close of the 22nd century. (TOS reference: Spaceflight Chronology)
Spaceflight Chronology based the Declaration-class class on an image originally designed by Matt Jefferies during the early pre-production stage of Star Trek. After the show was cancelled, the design was considered for use in a planned, but never produced, sci-fi television series by Gene Roddenberry. A portrait of the ship later appeared in Star Trek: The Motion Picture, as the USS Enterprise, which Star Trek Maps developed as the Starliner and UESP Enterprise and other sources have since referenced.
The Declaration-class, and thus this USS Enterprise, may be the same as the Starliner and the UESP Enterprise/USS Enterprise (XCV-330). However the nose section is different (possibly due to a refit).