Star Trek's lore is insanely complicated... 900 episodes across 12 TV series, plus 13 movies, all in a single universe. One of my favorite parts of the lore is the little details (and occasional direct depictions thanks to time travel) we get about Earth's history leading up to the birth of the Federation.

In either 1992-1996 (pre-retcon) or sometime after 2022 (post-retcon), genetically engineered warlords started conflicts around the world, most notably Khan Noonien Singh, who enslaved large populations and, upon defeat, escaped on a primitive spaceship. The 2020s see growing unrest and riots over severe income inequality, eventually leading to a second American Civil War. These conflicts combine into World War III, which lasts from roughly 2026 to 2053, until finally the factions launch their nuclear arsenals, killing 30% of Earth's population and destabilizing global governments.

In the early 2060s, while the world is still recovering from the "post-atomic horror", Zefram Cochrane leads a team of engineers developing a faster-than-light "warp drive". On April 5, 2063, the test flight of the the USS Phoenix, Earth's first warp-capable ship, attracts the attention of the Vulcans, a logic-worshipping alien race from a nearby planet who had been observing earth but waiting for this moment to make first contact. A Vulcan cruiser lands on Earth to meet the Phoenix, revealing to everyone that humans are not alone in the universe. Over the next century, Earth gradually forms a world government, eliminates poverty, and establishes diplomatic relations with nearby planets.

In 2154, attacks by the Romulan Star Empire lead to a joint operation between the planets Earth, Vulcan, Andoria, and Tellar to expose their meddling in interstellar politics. These nations form the Coalition of Planets (basically space NATO) for mutual defense later that year. In 2161, after winning a war against the Romulans, the Coalition becomes the United Federation of Planets, a post-scarcity socialist space confederation. Earth becomes the Federation's capital planet, and is considered a utopia. The Federation goes on to be a major power in the galaxy for around 900 years, expanding its borders through diplomacy and aid.

A recurring theme in all of Star Trek's depictions of the 21st century is how things get worse before they get better, and how those lessons from history enable us to build the optimistic future that most of the series depicts. It's really inspiring to imagine that even though things seem so bleak in the present, a better world could emerge from it all, if we fight for it.