After its victory in the violent Earth-Romulan War, the United Earth (UE) helped to establish a larger, more peaceful organization. At the First Babel Conference of 2161, the new United Federation of Planets was created by uniting the nations of United Earth, the Vulcan Confederation, the Andorian Hegemony, and the Tellarite League. A new combined interstellar force, the Federation Starfleet, was formed, with combined defensive and scientific roles. The powerful UE Stellar Navy formed the core of Starfleet, along with ships from the other members' defensive and exploration forces.

Many historians consider the late 22nd century a golden age for Starfleet. No longer facing the Romulan threat or other credible adversaries, the new Federation could focus on more peaceful, productive activities. Civilian colonization, made possible by the huge surplus of matter/antimatter-powered vessels after the war, stimulated the expansion of the Federation's borders. Likewise, missions of exploration expanded known space ever further from the Homeworld Core.

Federation Core Worlds, 2170

Although Starfleet inherited more than 100 warships from the militaries of Federation members, starships of an entirely new design lineage were developed in its first decade. The new designs were mostly derived from Earth-based engineering principles but also incorporated elements of Vulcan and Andorian design. Instead of having large tubular hulls containing all sections and closely attached warp nacelles, these new ships had separate hulls for command and engineering with nacelles mounted on long pylons. Starships became much smaller and more efficient (compare the massive 500,000-ton Conqueror-class cruiser of 2159 with the 70,000-ton Moskva-class cruiser of 2177) but also more numerous. By the end of the 2190s, starships more closely resembled the recognizable saucer-and-cylinder design that endured for the next 175 years. Technological advances developed for Starfleet ships were also applied to civilian designs like the Sozvezdie-class transport, which accelerated the movement of people and goods among Federation worlds, and allowed the founding of even more distant colonies.

Starfleet's ships of the late 22nd century were the most capable exploratory and defensive vessels in known space. Although less developed by modern standards, they had the most advanced technology and most powerful weapons of their time. They undertook extraordinarily bold missions of exploration, far beyond the Federation's borders. Legendary ships, such as the Daedalus-class cruiser and the Gagarin-class light cruiser, are still remembered throughout the Federation.