In this connect wall are 16 words. There are 4 groups of these words; your first job is to find these 4 groups and name them.
The second part is determining what 1 thing groups those 4 categories together.
Note: The knowledge tag is mainly for one of the categories, but a few other words might require external knowledge.
Rapids Cardinal Southwest Earthquakes
Prop Smart Brain Feathered
Rotary Delta Home Jet
Galaxy Dynamo Tweet Cellular
Partial solutions are welcome!
Hint: The final answer is a bit of a pun, especially in the "phone" category. It's obscure in the soccer teams, but very prominent in the plane/bird categories.