I have been using a KMZ file that has every county in the state of Texas throughout the state's history. I can choose a date on a timeline and see the county boundaries as they were set on that date. I can click on the county and get a popup showing the date it was created or last changed, which neighboring counties it added territory from or ceded territory to, and more. I can also choose which county or counties I want displayed from that date, so if I want to make a map focusing on a specific county or set of counties, I can. If it helps for the purpose of answering my question, the KMZ file was obtained here: https://digital.newberry.org/ahcb/
In Google Earth Pro and in ArcGIS Explorer Desktop, I can do everything with this KMZ file stated above. However, I require basemaps that Google Earth Pro does not have and that no longer work with ArcGIS Explorer Desktop, which is quite old. I am checking out QGIS. While it will import the KMZ and let me choose a date for the map, that's all I've gotten it to do. I can't see any way to select/unselect individual counties to be displayed. Whereas Google Earth Pro and ArcGIS Explorer Desktop listed each polygon (county) in the layer as a separate object with its own properties, QGIS simply shows a single mass layer (see the image below). I also don't see any way to access the popup information.
To add the KMZ into my QGIS project, I'm dragging the file into the map pane. The "Add layers to a group" and "Show system and internal tables" checkboxes don't have any apparent effect.
Can someone tell if if there is a way to make this KMZ file fully functional in QGIS, the way it is in Google Earth Pro and ArcGIS Explorer Desktop, with individually selectable polygons and notes, and if so, how?