I\'m trying to display multiple historic shape boundaries on a google map via Google\'s API using JS. I have one KML file displayed correctly currently, but I\'d like to hav
You can display one in each KmlLayer, but you can't control them other than to hide/show them.
There is a limitation, at some point the internal URL request (which includes all of the individual KmlLayer urls) exceeds a limit, and none of them display. Described in the documentation:
There is a limit on the number of KML Layers that can be displayed on a single Google Map. If you exceed this limit, none of your layers will display. The limit is based on the total length of all URLs passed to the KMLLayer class, and consequently will vary by application; on average, you should be able to load between 10 and 20 layers without hitting the limit.
You could import your KML into FusionTables, display it in a FusionTablesLayer and control the styling and display via the Google Maps Javascript API v3 (again there are limitations, but seems more likely to work that one hundred KmlLayers)
My answer to this question: Highlight country around the border from your search area only contains an example with two different styles, one for the center (blue border) and one for the surrounding counties (red).