How do I disable my location in safari?

I am currently living in Mexico but am from the U.S. Very often when I surf a website, especially a retail website, I am automatically directed to the Mexican equivalent or am unable to visit the U.S. site altogether. Is there a way to prevent websites from knowing I am in Mexico so that I am directed to the US web page? I've tried reseting safari, I've disabling location in system preferences date and time to no avail. For example, I am trying to shop Sears for Black Friday and all I get is "Acess Denied" You don't have permission to access "http://www.sears.com/" on this server.