Country State Select is library which gives you all the country names and when you select any country then it also create the other select box with all the states name of that country
Country State Select is released as a Ruby Gem. The gem is to be installed within a Ruby or Rails application. To install, simply add the following to your Gemfile.
Run bundle install and don't forget to restart your server after you install a new gem.
Contributing to Country State Select
Fork, fix, then send me a pull request.