Could be just a glitch at Google. HOWEVER...
Change your password, NOW, just in case. You might want to set up 2-step verification too.
Mine shows my Mac at home but it also shows it in Beaumont, 16 miles away, because my ISP (Time Warner) is there.
However, I don't think that's the case here. I mean Texas and Chicago?
A network card is the device used to get online, either ethernet or wifi.