How to install USA International keyboard option on Ubuntu Gnome 16.10
Solution 1:
Adding a new keyboard option to Ubuntu Gnome is not very intuitive and can be rather frustrating for that reason.
For example, one does not add a keyboard under System Settings > Keyboard.
Instead the option is located under System Settings > Personal > Region & Language > Input Sources > +
When one clicks the + sign one will see a list of languages and this is where some confusion and frustration may ensue: This is NOT a list of keyboard options, so do not peruse this rather lengthy list looking for your desired keyboard option.
Instead, click on the language you want. When you do that a new list will appear containing the list of keyboards available for that language.
From that list click your selection then click the Add button.