Weird email??

So I just got a prevented sign in email from Google saying that my gmail account was accessed from some place in the US.

It was from this ip: [font=Tahoma, Verdana, Arial, sans-serif]64.235.42.100[/font]

[font=Tahoma, Verdana, Arial, sans-serif]I have since changed all of my passwords on other sites etc but what could this be? [/font]

[font=Tahoma, Verdana, Arial, sans-serif]I'm pretty sure that I don't have any online beef with anybody to want to do this to me. I'm thinking that I may have been key logged or something.[/font]

[font=Tahoma, Verdana, Arial, sans-serif]If you could find out anything about this please let me know.[/font]

[font=Tahoma, Verdana, Arial, sans-serif]thanks[/font]

Dammit my IP is now public.
Jk, well did you use your phone to log in with it?
Are you the same state as the IP?

Same thing happened to me , some fucker from Canada cracked my password since it was relatively simple and tried to access all my accounts. Luckily that was my only weak pass I had. 

Crazy shit , i guess someone had beef with me on xbox