Is it possible to layer georeferenced maps over a base map in ArcGIS Online?

[KathrynCross1]

Hi there - Is there a way to bring a georeferenced image (like a map) into ArcGIS Online as a layer rather than as it's own base map? It would be extremely helpful if ArcGIS Online had this capability. For example, I'm comparing a 1920s landscape to the contemporary urban landscape. I would like to show this in a Story Map, but putting the map and current aerial imagery side by side really doesn't do it justice. This is easy to do in Pro, but, frustratingly, doesn't seem to be an option in ArcGIS Online. Thank you!

[Katherine_Clark · Accepted solution]

You can do this, all you have to do is load the georeferenced image as a tile layer. 

[KathrynCross1]

Ok, not sure what I did differently, but it's working now. Thanks!