Johnston Jacob "Jake" Green, Jr. (portrayed by Skeet Ulrich) is the oldest son of the Green family and pivotal character of the series. Jake was once a member of Jonah Prowse's group of survivalists; after a botched armed robbery job, in which Chris Sullivan (Jonah's son, and brother of Jake's girlfriend Emily Sullivan) was killed, Jake fled Jericho. Five years later, Jake returned to Jericho to pay his respects to his recently deceased grandfather and to claim the money his grandfather left him. Because of the problems in their relationship, his father refused to hand over the money, and Jake was leaving town again when he witnessed the destruction of Denver.

Jake was initially an unlikely hero, but his checkered past helped in Jericho's trying times. He took charge of getting people to safety, and eventually people came to look upon him as a leader. Over time he and his father repaired their relations. With his father's blessing, Jake put together the Jericho Rangers to help keep Jericho safe. Jake frequently left Jericho for supplies or information, and on other missions including rescuing his brother from New Bern, training the Rangers in gun skills, and defending the town from Ravenwood and the New Bern Army. Although he is impulsive, he is also intelligent, often coming up with ideas that help the town.

In Season 2, with the garrisoning and reconstruction of Jericho by the A.S. Army, the area's military commander and chief administrator Major Edward Beck recognized Jake's role as "the guy" – the one the others follow and listen to in the heat of conflict – and consequently appointed him Sheriff of Jericho. Jake and the rest of Jericho witnessed the domination of the Allied States of America and Jennings & Rall over the town and the country at large, with Jake knowing first-hand how dangerous Jennings & Rall were when it came to business dealings. Having previously been deliberately misleading and vague about his past, Jake came clean to Eric and explained what he did during his absence: Jake served in the military and navy, and later as a private military contractor for Ravenwood in Iraq and Afghanistan (thus explaining how Jake is shown to be accurate with a revolver at a distance and a skilled aircraft pilot). He left the service of J&R and vowed never to return after a severe massacre in Iraq which he and other Ravenwood soldiers took part in (his reluctance so extreme it was to the point his passport is flagged for non-cooperation on an undercover mission against Ravenwood); something that has continued to haunt him as he killed several innocent civilians, including an innocent child.

Jake secretly worked with Robert Hawkins, whom he eventually saw as a friend, to get the last remaining nuclear bomb from the September Attacks to the Independent Republic of Texas, thus exposing the conspiracy behind the attacks. In doing so, however, Jake and Hawkins inadvertently started the Second American Civil War.

Robert Hawkins (portrayed by Lennie James) was, during most of Season 1, a complete enigma; with no-one sure whether he was a good guy or bad guy. He had secrets that he was unwilling to share, even with his family. His history had estranged him from his wife and children, but in truth they are the only ones he cares about (demonstrated as, when he realized the September Attacks were coming, his first thought was to get his wife and children to safety).

Hawkins moved to Jericho with his wife, Darcy, and his two children, Alison and Samuel, three days before the attacks. He paid cash for the "Thompson house", leading to much gossip around the town about his background. Hawkins claimed he was a former police officer from St. Louis, Missouri, and explains his knowledge and expertise comes from having received Department of Homeland Security training after the September 11, 2001, attacks. In truth, the family had moved from Washington, D.C. When cornered, Hawkins claimed to be working undercover for the FBI to learn more about "suspicious contacts in this area" that may be linked to the Attacks.

Unknown to the rest of the town, Hawkins is deeply involved in clandestine activities. These include secret communications with unknown persons through a locked laptop computer, the monitoring of shortwave radio messages, and the storage of a large unmarked barrel containing the 20kt nuclear device that he was assigned to deliver to Columbus, Ohio, and detonate. He is later contacted by his associates, who know that he is lying to them.

Though his family initially did not know the truth, they keep a low profile and constantly rehearse their cover story and, later, he decides there should be no secrets between them, regardless of the dangers, and reveals the truth to them, and to Jake: he is a CIA deep-cover covert operations officer and a U.S. government agent who took part in Project Red Bell, a task force sent undercover to recover a shipment of stolen Russian warheads and stop the bombing. Even though he failed in that, he still had one of the bombs which could be used to uncover the conspiracy that started it all. Hawkins proves his loyalty to Jericho over the course of Season 1.

In Season 2, Hawkins and Jericho saw the rise of ASA and its dominance over the country. Seeing ASA was attempting to dominate the country and bury the truth behind the Attacks, Hawkins and Jake teamed up to deliver the bomb to the Independent Republic of Texas and expose the conspiracy, and in so doing started the Second American Civil War.

Gray Anderson (portrayed by Michael Gaston) is the owner of the Jericho salt mines, and Mayor Johnston Green's main political rival. After the September Attacks, Gray is among those who go out to scout the country for information. Gray later returns, having witnessed the confusion, devastation and atrocities in the aftermath of the Attacks, and gains considerable respect for having seen first-hand the dangers outside of town. Gray brings with him the news that New York City has survived the attacks, but Washington D.C. has not, nor has Lawrence. Eventually, Gray wins election as Mayor, defeating Johnston. One of his first priorities as Mayor is to find a new power source, leading to the construction of a windmill. Gray is portrayed as more of a businessman than a leader of the community, and is seen to crack under pressure, leading others (Johnston, Eric, Jake etc.) to take their own initiative; for example, when Gray is near surrender during the early stages of the New Bern War, the Jericho Rangers take charge and defend the town against the invasion.