Some basic NFL franchise history might be worth noting:
The Steelers and Giants are both “original” franchises that date back to the 20s or 30s, and both have been family-owned since their creation. The Rooney family owns the Steelers, and the Mara family owns the Giants. The two families have also inter-married. The most famous offspring are the Mara sisters, Kate (from House of Cards) and Rooney (from Girl with the Dragon Tattoo.) Their mother is a Rooney, their father a Mara, and it’s pretty obvious where Rooney got her first name from.
Two new expansion teams were created in the same year in the mid 90s, the Carolina Panthers and Jacksonville Jaguars. They were both given extremely favorable expansion bonuses, as in they got to choose players to just take from the other teams at their inception. This led to both being very strong very quickly, highlighted by the fact that both teams made it to within a single game of the Superbowl in their second year. After the 90s, the Panthers have ranged from mediocre to good, while the Jaguars have become the worst team in the league.
In the early 80s, the owner of the Baltimore Colts moved his franchise without letting the fans know. He boxed up all the team’s stuff and moved it out on trucks in the middle of the night, relocating the team to become the Indianapolis Colts. (Where they remain to this day.) As you might guess, fans in Baltimore were PISSED, and many still hold a grudge.
In 1996, the owner of the Cleveland Browns moved that franchise to Baltimore, renamed the team to the Baltimore Ravens, and gave up the rights to all Cleveland Browns history. (Records, championships, etc…) Cleveland was promised a new team in the coming years, which they got in 1999. Because the Panthers and Jaguars were given “instant-contender” status at their creation via the favorable player selections, the poor Browns didn’t get anywhere near as favorable deal and have been stuck in mediocrity (at best) ever since.
Houston (Texas) used to have a franchise named the Houston Oilers. They weren’t that great, and eventually the franchise moved to Tennessee and was renamed to the Tennessee Titans. The Titans then promptly went to the Superbowl, but sadly lost. This was actually referenced in the movie Cast Away with Tom Hanks. The character is from (or near) Nashville, and is stunned to find out in his several year absence that he got a local team out of the blue, and that they went to the Superbowl.
Houston was given a new expansion team in 2002, the Houston Texans. Although the Oilers history (records, championships, etc…) was not moved to Tennessee when the franchise moved, the people of Houston didn’t much care for that history and so the Texans started fresh, from scratch. Their initial setup was better than Browns, but not as good as the Panthers and Jaguars, and have ranged from awful to pretty good since their creation. Better than the Browns, certainly, but not as good as the Panthers and Jaguars in the 90s.
Los Angeles has long been the dream for the NFL front office, who desperately wants a team there. In the 80s (into the 90s?) there were two teams in LA: the Rams and the Raiders. Both have since left LA, becoming the St Louis Rams and the Oakland Raiders. The NFL is ever eager to get someone back there, though, and current “contenders” for the forced move are the Jaguars – because they suck so hard – and the Chargers, who are good but have kind of a weak fanbase in San Diego. The NFL doesn’t care who moves there, they just want a team in LA because it’s such a huge media market. (Second only to New York City, I believe.)
The introduction of the Texans in 2002 meant that the league finally had 32 teams, so they realigned the divisions. This realignment changed the structure from six divisions to eight divisions, with four teams in each division. During this realignment they made steps toward putting teams in geographically appropriate divisions, like the Arizona Cardinals moving from the East to the West.