Loading ArcGIS Service & GeoJSON

This block demos a few things:

Loading basemaps of Scott County, KY created in ArcGIS and served from ArcGIS Server using Esri-Leaflet. The amount of dialog boxes one has to go through to style features in ArcGIS makes the styling process a bit clunky, but it’s possible to create a nice basemap in ArcGIS. The layer switcher shows two. The first one is based on OpenMapSurfer’s style. The second is based on Stamen’s Toner.
Loading external GeoJSON data with D3. I had never used this method before until I came across Ian Johnson’s tutorial series “Working with spatial data for the web”. In the past I’ve used leaflet-ajax. It has worked well for me, but I like the idea of having D3 at my disposal and not having to load another library. Furthermore, while I do appreciate Calvin Metcalf’s work on leaflet-ajax, D3 has a larger community contributing to it so I’m tempted to move to D3 for loading data.