Conversation so far:
who are the 32 teams in the nfl
how many players are allowed on an NFL team roster during a regular season
During the regular season, each NFL team is allowed a maximum of 55 players on its roster
are any nfl teams based in a foreign country
Every NFL team is based in the contiguous United States.
which team is the most valuable of the nfl franchise
According to Forbes, the Dallas Cowboys, at approximately $5 billion, are the most valuable NFL franchise and the most valuable sports team in the world

Question: when did the two conferences merge
Self-contained rewrite: when did the national football conference and the american football conference