JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://maps.googleapis.com/maps/api/js?v=3.&amp;ext=.js"></script>
<div id='map_canvas'></div>

CSS

body, html, #map_canvas {
    height: 100%;
    width:100%;
}

JavaScript

var data = [{
    "lat": "54.508869",
    "lng": "-6.2925",
    "FORENAME": "Ellen",
    "SURNAME": "Wetherall"
}, {
    "lat": "54.5088",
    "lng": "-6.292547",
    "FORENAME": "Annie",
    "SURNAME": "Beckett"
}, {
    "lat": "54.50",
    "lng": "-6.29",
    "FORENAME": "William",
    "SURNAME": "Beckett"
}, {
    "lat": "54.509",
    "lng": "-6.292547",
    "FORENAME": "John",
    "SURNAME": "Wetherall"
}, {
    "lat": "54.508869",
    "lng": "-6.2",
    "FORENAME": "Henretta",
    "SURNAME": "Wetheral"
}, {
    "lat": "54.59",
    "lng": "-6.247",
    "FORENAME": "Mark",
    "SURNAME": "Wetherall"
}, {
    "lat": "54.508869",
    "lng": "-6.27",
    "FORENAME": "Thomas",
    "SURNAME": "Wetherall"
}, {
    "lat": "54.508869",
    "lng": "-6.2947",
    "FORENAME": "Robert John",
    "SURNAME": "Wetherall"
}, {
    "lat": "54.50869",
    "lng": "-6.292547",
    "FORENAME": "Thomas",
    "SURNAME": "Wetherall"
}, {
    "lat": "54.508869",
    "lng": "-6.29547",
    "FORENAME": "Lizzie",
    "SURNAME": "Wetherall"
}, {
    "lat": "54.50869",
    "lng": "-6.29547",
    "FORENAME": "Sarah",
    "SURNAME": "Thompson"
}, {
    "lat": "54.508869",
    "lng": "-6.292547",
    "FORENAME": "Mary L",
    "SURNAME": "Thompson"
}, {
    "lat": "54.508869",
    "lng": "-6.292547",
    "FORENAME": "Annie",
    "SURNAME": "Thompson"
}, {
    "lat": "54.508869",
    "lng": "-6.292547",
    "FORENAME": "Anne",
    "SURNAME": "Thompson"
}, {
    "lat": "54.508869",
    "lng": "-6.292547",
    "FORENAME": "James",
    "SURNAME": "Thompson"
}, {
    "lat": "54.508869",
    "lng": "-6.292547",
    "FORENAME": "Joseph",
    "SURNAME": "Thompson"
}, {
    "lat": "54.508869",
    "lng": "-6.292547",
    "FORENAME": "Sarah",
    "SURNAME": "Thompson"
}, {
    "lat": "54.508869",
    "lng": "-6.292547",
    "FORENAME": "Annie",
    "SURNAME": "Mulholland"
}, {
    "lat": "54.508869",
    "lng": "-6.292547",
    "FORENAME": "John",
    "SURNAME": "Mulholland"
}, {
    "lat":...