Without bothering to do any supplementary research:
Some of them are self-evident, such as the Houston Texans.
Baltimore Ravens: IIRC, Baltimore was the primary residence of Eddy A Poe, who wrote “The Raven”.
Green Bay Packers: Lambeau was running low on funds, so he arranged for this guy who owned a meat packing company to invest in the team. The primary condition of the investment was that the team be named the Packers.
Chicago Bears: The Cubs were already established in Chicago, so Halas went with another ursine name, I guess for nominal familiarity.
New England Patriots: anyone who roots against them in unPatriotic! ;-p