Google Geo Chart for States.

HTML

<script src="https://www.google.com/jsapi"></script>
<div id="visualization" style="margin: 1em"> </div>

CSS

#visualization svg path[fill^='none'] {
  stroke-width:1px;
}

JavaScript

google.load('visualization', '1', {'packages': ['geochart']});
google.setOnLoadCallback(drawVisualization);

function drawVisualization() {
  var data = google.visualization.arrayToDataTable([
    ['State', 'Population'],
    ['Lazio', 19581477],
    ['Lombardia', 19581477],
    ['Veneto', 19581477],
    ['Abruzzo', 15181477],
    ['Puglia', 11581477],
    ['Calabria', 19581477],
    ['Sicilia', 19581477],
    ['Toscana', 19581477],
    ['Umbria', 19581477],
    
  ]);
  
  var opts = {
    region: 'IT',
    displayMode: 'regions',
    resolution: 'provinces',
    datalessRegionColor: 'transparent',
    width: 640, 
    height: 480
  };
  var geochart = new google.visualization.GeoChart(
      document.getElementById('visualization'));
  geochart.draw(data, opts);
};