John,
My wife has Samsung & I have LG (both smartphones). Both charger plugs are interchangeable.
This is the connection plug to our phones:

This is my LG outlet plug end. (S. Korea has 220 voltage hence the 2 prong plug) The outlet plug detaches from the cord via a USB connection. My wife's Samsung charger doesn't have this USB attachment.
I plug my LG or my wife's Samsung into my PC for charging or transferring files.
I don't know what connection plug is used in the US.