Races and cultures
The Alpha Quadrant is home to a number of major and minor political entities including the United Federation of Planets, whose headquarters is located on Earth on the border with the neighboring Beta Quadrant. Most of the Federation's member planets are located in the Alpha Quadrant, including Betazed, Deneva, Bolarus, Trill, and Benzar. In its entirety, the Federation spans over 8,000 light years in both the Alpha and Beta Quadrants.The Federation's biggest ally, and one time enemy, the Klingon Empire, also occupies a few systems in the Alpha Quadrant, but its largest sphere of influence is the Beta Quadrant. 
Some smaller powers in the Alpha Quadrant include the Orions, the Tholian Assembly, the Breen Confederacy, the Gorn Hegemony, the Tzenkethi, and the Ferengi Alliance. However, one of the largest political entities in the Alpha Quadrant is the Cardassian Union.
Situated in Sector 45833, bordering the Bajoran sector, the Cardassians occupy a large number of star systems and planets, and also shares borders with the Ferengi and the Breen. Throughout the 24th Century, relations between the Cardassians and the Federation have often been strained with the Federation-Cardassian War between the 2340s and 2360s, though that war was ended in 2366 and the two worked towards a tenuous peace.
That peace ended in 2373, when the Cardassians entered into an alliance with the Gamma Quadrant's Dominion. By the end of the year, the Dominion War broke out and the Dominion managed to occupy many Alpha Quadrant worlds including Betazed. However by 2375, the Federation Alliance, comprising the Federation, the Klingons, and the Romulan Star Empire, managed to defeat the Dominion and occupy Cardassia.
The Alpha Quadrant contains a number of astronomical objects and anomalies, including the Bajoran wormhole which was found near planet Bajor in 2369, which unlike the Barzan wormhole discovered in 2366, was a stable wormhole, which connected the Alpha Quadrant to the Gamma Quadrant which is over 70,000 light years from Bajor.
Lying near the Bajoran system is a zone of intense plasma storm activity known as the Badlands in Sector 21305. First discovered by the USS Enterprise in 2268, the Badlands has proved to be treacherous to navigate and has also provided a haven for smugglers and terrorists. During the early 2370s, the Maquis used the Badlands as a base of operations for the war on the Cardassians.
The Alpha Quadrant also contains a number of nebulae and stellar clusters, many of which have unique properties, such as the Amargosa Diaspora, the Helaspont Nebula, FGC-47 and the Briar Patch. Other phenomena are also a rare occurrence in the quadrant such as the Black Cluster, the Mar Oscura, the Typhon Expanse and the Epsilon Pulsar Cluster, which have all been mapped by Federation starships and listed as potentially hazardous to shipping.