The United Federation of Planets (UFP) was founded in 2161 by Human, Vulcan, Andorian, and Tellarite governments as an interstellar republic. Among the founding principles of the Federation were universal equality, liberty, rights, space exploration, along with the sharing of knowledge and resources in peaceful cooperation.
By 2371, the Federation had spread itself across 8,000 light years of the Alpha and the Beta Quadrants in the Milky Way galaxy, to include some 150 member worlds and about a thousand colonies.
The capital world of the Federation is Earth in the Sol star system. The office of its President's is situated in the Place de la Concorde in Paris, France, although the President does not necessarily have to be Human, and can come from any species which has joined the Federation. Meanwhile, its legislative branch, along with the headquarters and training facilities of its space fleet, Starfleet, are in San Francisco, USA.