Basic GeoJSON example

<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>Load GeoJSON</title>

<div id='map'></div>
<script>
var geojson = [
  {
    "type": "Feature",
    "geometry": {
      "type": "Point",
      "coordinates": [-77.03238901390978,38.913188059745586]
    },
    "properties": {
      "title": "Mapbox DC",
      "description": "1714 14th St NW, Washington DC",
      "marker-color": "#fc4353",
      "marker-size": "large",
      "marker-symbol": "monument"
    }
  },
  {
    "type": "Feature",
    "geometry": {
      "type": "Point",
      "coordinates": [-122.414, 37.776]
    },
    "properties": {
      "title": "Mapbox SF",
      "description": "155 9th St, San Francisco",
      "marker-color": "#fc4353",
      "marker-size": "large",
      "marker-symbol": "harbor"
    }
  }
];

L.mapbox.map('map', 'examples.map-9ijuk24y')
  .setView([37.8, -96], 4)
  .featureLayer.setGeoJSON(geojson);
</script>

</body>
</html>

https://api.tiles.mapbox.com/mapbox.js/v1.6.1/mapbox.js