Display XY Data not honoring coordinate system of input coordinate system - I have tabular data with lat lon columns in an unknown geographic coordinate system I need to bring into ArcMap and compare to a feature class with a known coordinate system. I used Display XY Data three different times, each time specifying a different geographic coordinate system (NAD27, NAD83, and WGS84) for the input data. I exported each to a new feature class and displayed them all on a map. I expected there would be a difference in the point locations between the NAD27 and the NAD83 points, but all 3 essentially fell on top of each other. Is there something I don't understand about the Display XY Data functionality, or is it not honoring the specification of input data coordinate systems, or what??