This refit of the old Constitution-class is best evidenced via the U.S.S.Enterprise, under the command of a then-Admiral Kirk, circa 2271.
This class of starship featured an increase in crew compliment, approximately 520 persons, from its predecessor. Also new to this refitted class were a virtual upgrade of all key systems. A new bridge module was installed and main engineering received an upgrade, along with the replacement of the warp nacelles.
In 2285, just prior to its scheduled retirement, NCC-1701 was destroyed by Kirk, to prevent his ship from falling into Klingon hands.