2376:

The Dominion War ends as Federation, Klingon, Romulan, and eventually Cardassian forces retake Cardassia Prime. The Dominion surrenders and the female changeling turns herself over to Federation forces.

After the war is over, millions of Cardassians are dead and several Cardassian cities are destroyed. The Klingons return to their space, while the Romulans must return to rebuild their empire which has also suffered greatly at the hands of the Dominion. Once again the Romulans enter a period of isolation which would lead to their downfall.  

Colonel Kira Nerys is put in charge of Station Deep Space 9 when Captain Benjamin Sisko mysteriously disappears on Bajor. Expatriot Cardassian Elim Garak returns to his home world after many years of exile to rebuild his world.

2377:

The Cardassians have their first open election in over a century and Elim Garak is elected by a landslide as the new Legate of Cardassia. He will hold that position for 15 years, until his death.

Later that year Federation engineers, medical personnel, and scientist are stationed on Cardassia Prime to help with the rebuilding of the "new" Cardassia. Cassidy Sisko gives birth to a daughter and names her Sara. A weakened Romulan Empire falls to the Borg. The Borg now have cloaking technology.

2378:

Romulan refugees ask for sanctuary, which the Federation grants to them. Hundreds of Romulans relocate to Earth while a few choose to return to Vulcan.

2379:

Bajor joins the United Federation of Planets. The Cardassian government signs a peace treaty with Bajor and Legate Garak offers a broadcast apology to the Bajorans for the crimes committed against them by the Cardassians. A peace treaty is signed by The Federation, Cardassia, and the Breen. The Klingons refuse to sign the treaty because of their mistrust of the Breen.

2381:

The federation accepts Cardassia Prime as a new member. The Borg attack the Klingon Empire. They a barely defeated but not before 523 ships and thousands of lives are lost including Federation Ambassodor Worf .

2382:

The Borg once again attempt an invasion of Federation space. Once again they are defeated thanks to Admirals Picard and Riker.

2385:

The U.S.S. Voyager, which was thought lost, returns to Earth after being stranded in the Delta quadrant for 14 years with a crew composed of Federation, Maquis, one Talaxian and an unassimilated Borg.

The Federation starts to put cloaking devices on its ships since any treaties with the Romulan Star Empire are null and void considering the Romulan Empire no longer exists.

2387:

Marking the tenth anniversary of the end of the Dominion War, the shape-changer Odo returns to Deep Space Nine as the leader of the Dominion. He signs the Bajoran peace accord to grant a permanent peace between the occupants of the Alpha quadrant and the Dominion. Among those attending are Ambassador Spock, Chancellor Martok, and Grand Nagus Ishka, the first female ever to hold that position.

2391:

The "Emissary" returns to Bajor, and a new age of tranquility begins as Benjamin Sisko helps the Bajorans to find the inner peace they have been without for almost a century.

The first Cardassian to attend Star Fleet academy, Ra'Jar (son of Damar, the former Legate of Cardassia) graduates second in his class.

2394:

A Borg ship is captured in the former Romulan neutral zone. Federation and Vorta scientists, along with the former Borg drone Seven of Nine, are able to integrate the technology and use it in the construction of newer Federation vessels.

2396:

Transwarp technology is finally perfected. Those responsible are the former Borg Drone Seven of Nine, Captain Geordi LaForge, Professor Leah Bramhs, Professor Miles O'Brien, and Dr. B'Elana Torres.

2398:

The first Federation vessel with a transwarp drive leaves the Utopia Planatia ship yards on Mars. It is a new class of star ship and the first of its kind -- the U.S.S. Hikaru Sulu with a crew of 1,300.