Google has multiple datacenters around the globe and keeps opening new ones.
In the US, there are 3 major zones: East, Center and West.
There are 2 data centers in eastern zone, one in South Carolina and another one in Virginia.
More information about Google Data Centers and the next locations (Finland, Los Angeles, Osaka, Taiwan) can be found here.
When deploying an environment to cloud you should choose a datacenter that is closest to your / your client's location.
You can test and measure the latency to all the world datacenters from your location in the following link: http://www.gcping.com/
It's Google native tool that works the following way: "Your browser makes HTTP requests to
f1-micro instances in each region. The median time between request and response is shown.
The global row uses a Global HTTP Load Balancer to route requests to the nearest healthy instance."