wat.geojson

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "name": "USA",
        "fill": "#00FF00",
        "fill-opacity": "0.2"
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [
              -171.791110603, 18.91619
            ],
            [
              -66.96466, 18.91619
            ],
            [
              -66.96466, 71.3577635769
            ],
            [
              -171.791110603, 71.3577635769
            ],
            [
              -171.791110603, 18.91619
            ]
          ]
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "name": "Missing `-` sign on Longitude",
        "fill": "#ff0000",
        "fill-opacity": "0.2"
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [
              171.791110603, 18.91619
            ],
            [
              66.96466, 18.91619
            ],
            [
              66.96466, 71.3577635769
            ],
            [
              171.791110603, 71.3577635769
            ],
            [
              171.791110603, 18.91619
            ]
          ]
        ]
      }
    }
  ]
}

This is what happens when you leave off the - from your longitude. What should be within the green polygon ends up being in the red polygon.

Sadly, Github changed their support for GeoJSON styling, so the polygons are no longer styled red/green and this visualization is not as useful.