Google.com correctly detects that my ISP is located in Israel, and it's default behavior is to connect me to www.google.co.il. I believe people in other countries also experience this behavior.
If you want, for whatever reason, to get to the US site, google.com, where you can type in your search terms, you can point your browser to https://www.google.com/ncr.
However, if you are using things such as your browser's search bar, they likely are forwarding your query as "https://www.google.com?q=searchword1+searchword2+.......", which gets you to the redirected site. You could change ".com" to ".com/ncr", as you did when typing in the url directly, but that does not work since "https://www.google.com/ncr?q=searchword1+searchword2+......." does not work.
What worked for me was to change ".com" to ".us", and add "?gfe_rd=cr&gws_rd=cr&" in which case "https://www.google.us?gfe_rd=cr&gws_rd=cr&q=searchword1+searchword2+......." directs to the US server, google.com with the search terms entered as if you originated the inquiry from within the US.
Additionally, my own search start page, which was designed along these principles, gives you a choice of using the local, or the US server. This currently is working. Our search start page also gives you access to other search engines, and we recommend using Ixquick as a replacement for Google.