During America's "Old West" in the 1800's, cowboys reached for their guns as often as a yeoman reaches for a PADD. It was several centuries before the first energy based firearm would be invented, so these weapons still fired metal projectiles ("bullets"). However, for hundreds of years after their invention, guns could still only fire one shot before they had to be reloaded. The first step in the advent of a multi-shot firearm was the invention of the "paperbox" pistol, which had several barrels that could be turned by hand. Then in the middle of the 19th century, Samuel Colt developed his first "revolver". He named it such because the gun's magazine revolved each time the trigger was pulled, thus putting the next bullet into firing position without requiring manual intervention.

The first Revolver held only five bullets. This kind of pistol was found by law enforcers of the time to be quite effective in keeping the peace. One such law enforcer named Captain Walker wanted a version of the revolver with a longer barrel, so Colt made him a special revolver which later became known as the "Walker Colt". Over time, Colt modified the revolver to fire six shots without reloading and this "six-shooter" model became even more popular with law enforcers. Because of its reputation as the gun of the "lawman", Colt's six-shooter eventually became known as "The Peacemaker".

The relationship of the name Peacemaker with starships began with Earth's first manned mission to Mars in 2035. With the nations of Earth still at odds with one another, the United Nations managed to gather all the world's countries together to establish a colony on Mars as a solution to the Earth's overcrowding problem. In the hope that the mission would unite the Earth's nations in a common effort, the first manned interplanetary space craft was christened the Peacemaker.

The first Starfleet ship to bear the name Peacemaker was a Daedalus Class starship, christened USS Peacemaker NCC 1962. The Daedalus Class was a commonly used design in the early 22nd century. Unlike most later starships, the Daedalus Class had a spherical main hull. 

The Peacemaker's registration number NCC 1962 was originally NCC 196, but soon after being commissioned it was realised that the Daedalus Class Peacemaker was actually the second starship to bear the name, so a "2" was added to her registration number to reflect this. The last Daedalus Class ships are assumed to have been taken out of service by the end of the 22nd century.

 The Peacemaker's registration number NCC 1962 was originally NCC 196, but soon after being commissioned it was realized that the Daedalus Class Peacemaker was actually the second starship to bear the name, so a "2" was added to her registration number to reflect this. The last Daedalus Class ships are assumed to have been taken out of service by the end of the 22nd century.

The next Starfleet ship to be named Peacemaker (NCC 1962-A) was an Advance Class ship which succeeded the Daedalus Class USS Peacemaker upon decommission. The Advance Class ships were the first ships to employ saucer-like primary hulls and rear-facing shuttle bays. All Advance Class ships were decommissioned at the end of the 23rd century.

Peacemaker name, an Excelsior Class ship, NCC 1962-B. A large number of Excelsior Class starships were built over a period of more than 60 years, completely replacing the outdated Constitution and Advance Classes. The Peacemaker-B was commissioned in honor of the Khitomer accords, and served in the battle at Wolf 359, where she was lost. Excelsior Class ships are still currently in use by Starfleet. Upon the retiring of the Peacemaker-B, Starfleet commissioned another ship to carry on the name.

The latest starship in the Peacemaker ine is a Sovereign Class ship, USS Peacemaker NCC 1962-C. With the advent of the Dominion War and an increased threat from the Borg, The Sovereign Class ships were designed to be battle cruisers as well as scientific vessels. The Sovereign Class is the longest ship in the fleet, but it is still less massive than the Galaxy and Ambassador Class ships, leading to higher maneuverability.