I just recently came across this gem of a resource that provides links to external publicly available mapping information (see attached catalog). This is a great resource when you're looking to add a geospatial view into your dashboards to help it really resonate with the users of your app.
The catalog contains a listing of both secured and publicly available maps.
Here’s one way to use it:
Go to Access Constraints (Column I) and filter on “None (Public Domain Information)”
Go to Layer (Column D) and find a specific map layer (of course you can filter on other columns to narrow your search)
Cut and paste the URL from Open URL (Column M) into a browser. This will provide a web site where you can either download the map in various forms (spreadsheet, KML, shapefile, etc) or use an API to render the map through a web service