JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://maps.googleapis.com/maps/api/js?v=3&amp;sensor=false&amp;ext=.js"></script>
<div id="map-canvas" style="width:400px; height:472px;;"></div>
<div id="content-window"></div>

JavaScript

function initialize() {
    var myLatlng = new google.maps.LatLng(42.2625932, -71.8022934);
    // zoomControl:false,
    // zoom: 18,
    // Title: "Mass Districts",
    //  center: myLatlng
    var mapOptions = {
        zoomControl: false,
        zoom: 11,
        title: "Mass Districts",
        center: myLatlng
    };
    var map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);


    var kmlLayer = new google.maps.KmlLayer({
        url: "http://mapsengine.google.com/map/kml?mid=zHTaYadv8Mrs.kHqpg6p0mrlk&lid=zHTaYadv8Mrs.khlpCJFyVigQ",
        suppressInfoWindows: true,
        preserveViewport:true,
        map: map
    });

    google.maps.event.addListener(kmlLayer, 'click', function (kmlEvent) {
        var text = kmlEvent.featureData.description;
        showInContentWindow(text);
    });

    function showInContentWindow(text) {
        var sidediv = document.getElementById('content-window');
        sidediv.innerHTML = text;
    }
}
google.maps.event.addDomListener(window, 'load', initialize);