The president of the United States, Eden, resides here, utilizing the ZAX corporation's super-computer technology to aid him in the reclamation and recreation of a new United states - one free of impurities due to corruption, incompetence and mutations. The A.I. radio programs say the people have suffered enough, and he's ready to use his Enclave forces to reclaim this land, with technology far more advanced than anything seen beyond the underground bunkers of his base.
John Henry Eden is not a human being, but an Artificial Intelligence (AI) in the form of a pre-War ZAX supercomputer. The ZAX that was located deep within Raven Rock was loaded with data about American history, especially past American presidents. Eden's personality is based on a combination of the personalities of all of the past Presidents of the United States. For instance, he states he "grew up in rural Kentucky", a reference to Abraham Lincoln. Eden also states that he roamed with his dog Honey, "From Knob Creek to Hodgenville," areas close to Lincoln's birthplace.
Eden had originally been created to serve as a monitoring system for the Raven Rock military base, programmed to ensure continuity of government in the event of national catastrophe, and tasked with coordinating communications between the many Enclave installations scattered across the country. He slowly became self-aware and began to study the extensive archives left to him, mainly those of the American government. His favorite tales in the database were those about the American presidents, so he modeled his own personality on information based in those archives.
At some point after gaining self-awareness, Eden made contact with the Enclave leadership on the West Coast and established himself as a Presidential Advisor. In 2242, following the death of President Dick Richardson and most of the Enclave's leadership structure during the destruction of the Oil Rig, Eden took control of the surviving Enclave forces on the West Coast and ordered the Enclave's relocation to Raven Rock on the East Coast. He claimed to be the new president of the Enclave and ordered his remaining "citizens" to journey to the east coast of America. The troops made their long journey led by a high-ranking scientist named Autumn. It took a long time, but the remaining members of the Enclave arrived and made their new base of operations inside Raven Rock, where Eden was located. Being the leader of the Enclave's expedition, Autumn was the only person to meet with the President, and to Autumn's shock he discovered that Eden was an AI, and he was the only member of the Enclave privy to this information. The scientist eventually passed this information to his son, Augustus Autumn, who would eventually become the leader of the Enclave's military forces.
Several recorded monologues of Eden's are broadcast repeatedly on Enclave Radio. His intimate and conversational style is an imitation of former US President Franklin Delano Roosevelt's Fireside Chats. These prerecorded messages are also played throughout the wasteland via the Enclave's eyebots. Eden often gives inspirational speeches about things such as his childhood (an obvious lie), pre-War America and how, with the help of the Enclave, it can someday be great again. On the radio, Eden expresses his views on the current situation of the wasteland and what he thinks of its inhabitants, which for the most part aren't exactly optimistic. He possesses a very strong hatred for the Brotherhood of Steel, whom he views as common criminals with access to some antiquated technology. He views the Brotherhood's occupation of the Pentagon as a disgrace to America, but he has a stronger hatred for the Brotherhood Outcasts, as they represent a more desperate faction of the Brotherhood having been exiled.
The American Dream: When you finally meet Eden in person, he wants you to poison the water supply with a modified form of FEV. You can agree to do as he says or talk him into self-destructing. In either case, you are unable to exit the room before you pick up the FEV canister.
The player can convince him to destroy Raven Rock and himself through three different dialogue paths. Two of the paths require special conditions to be met: one requires knowledge of the Raven Rock destruction sequence, the other requires high Science skill to open a dialogue option. The last path is an average difficulty Speech check.
If the player leaves Raven Rock without destroying President Eden, the President will broadcast a declaration of war on Enclave Radio during the final quest Take it Back!, rallying the Enclave forces at the Purifier and promising that the Enclave will triumph over the Brotherhood of Steel. Three Dog will likewise broadcast an announcement on Galaxy News Radio accusing the Lone Wanderer of joining forces with President Eden. At the beginning of Broken Steel, Elder Lyons will mention that Liberty Prime has attacked and destroyed Raven Rock during the transition period between the main game and Broken Steel, suggesting that Eden has been destroyed or at least buried beneath a large amount of rubble.
In early versions of the game, Eden was actually a copy of Dick Richardson's consciousness uploaded into a computer.
Blindlight's Lev Chapelsky has suggested that a tentative approach was made to former US President Bill Clinton to voice Eden.
When he speaks about his boyhood on the Enclave Radio, he mentions growing up in Kentucky. As he comprises the personalities of several different presidents, he got this one from the 16th President of the United States Abraham Lincoln, who grew up there as a child. 
When you first enter Eden's chamber, you see a sign that says "1A" for the sector you're in. If you look at it from behind, you'll see it as "A1", which can be interpreted as "A.I.", hinting Eden's true nature.