3/30 Code (Full)

<!DOCTYPE html>
<head>
  <meta name="viewport" content="intial-scale=1.0, user-scalable=no"/>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyBkEjkS9E2RAIJodE6gFHseUQx8_Cx2AiE&callback=initMap"
    async defer></script>
  <style>
    body
    {margin:0;position:fixed;top:0;right:0;bottom:0;left:0; } 
    #map 
    {position:absolute; 
      width: 100%;
      height: 100%; }
    #mapid {height: 180px; }
  </style>
<link rel="stylesheet" href="/maps/documentation/javascript/demos/demos.css">
</head>
<body>
  
  <div id="map"></div>
  <script>
 
 //Creates Google Maps Background
    function initMap() {
        // Create a map object and specify the DOM element for display.
        var map = new google.maps.Map(document.getElementById('map'), {
          center: {lat: 38.434084, lng: -78.864970},
          scrollwheel: true,
          zoom: 30,
        	mapTypeId: "satellite",
          //rotates the map
          heading: 60,});}
    
//Importing/logging the data into the console
    d3.json("HillsideData.json", function(error, data) {
		console.log("data:", data);})
            
//Creates the overlay connecting the SVG and the map
    function OOverlay() {
//Adds a container when the overlay is added to the map 
      var overlay =  new google.maps.OverlayView();
      overlay.onAdd = function() {    
          var svg = d3.select(this.getPanes().overlayPanes).append("svg")
                        .attr("class", "Plots");
      console.log("function")}
    			
      		overlay.onAdd();
    
      overlay.draw = function() {
        
     		var plotgroup = layer.selectAll("svg")
        	.data(data)
        	//.each(transform)
     		.enter().append("svg")
        	//.each(transform)
        	.attr("class", "plot")
        	
        d3.select("svg").selectAll("rect")
        plotgroup.append("rect")
      		.data(data)
          .enter()
          .attr("x", d3.latitude)
      		.attr("y", d3.longitude)
     			.attr("length", 100)
     			.attr("width", 100)
      		.attr("fill", "brown")}

d3.select("svg").selectAll("rect")
    
 
  
   d3.json("HillsideData.json", function(err, data) {
      console.log("data:", data);
      
      var plots = g.selectAll("circle.dot")
        .data(data.features)
    
      })}

https://d3js.org/d3.v4.min.js