In a parallel universe, the USS Enterprise, registry number NCC-1701, was a Constitution-class Starfleet vessel used for exploration by the United Federation of Planets during the 23rd century. It was the "original" vessel named Enterprise, a lineage that would be followed by the Enterprise-D in the 24th century.
The USS Enterprise was commanded by Captain James T. Kirk. His first officer was Mr Spock while Leonard McCoy and Montgomery Scott served as ship's surgeon and chief engineer respectively. (COMIC: Assimilation²)