How to add points along a line by clicking on the line?

[AfsiMoaveni]

ArcGIS Desktop 10.6.1

I have a polyline (old railroad track). I'd like to add the train stops as points along it by clicking on the places. I have georeferenced historical maps as the background and can see the train stops on it.

In the construct points along a line, I have to select distances or equal distance, etc. I don't see an option for clicking.

If I just generate points (create a new point file and just click), then then points may not be on the line.

Thanks for any suggestions.

[LanceCole]

Afsi, 

If you enable snapping in ArcGIS you can snap to the line you are trying to place the point onto.  Take a look at Using snapping effectively in ArcGIS 10 for ArcGIS Desktop or Configure snapping—ArcGIS Pro.