I've only been using GIS for a couple of months so this is probably just a really basic/novice problem but I cannot for the life of me fix it.
The other day I managed, with a lot of finagling, to create a map out of an Excel spreadsheet I had made with lat/long in DD and a generic basemap. For some reason the data was not lining up with the basemap and I can't remember how I got it to work in the end - mostly a lot of trial and error. Unfortunately I moved the Excel source so when I reopened it later it had the whole red exclamation mark deal next to the data. I re-set the source but now it's refusing to line up and I CANNOT fix it. I've tried everything I can think of, including starting completely over. The dataframe and Excel sheet layer have the same coordinate system and I added the basemap after defining the coordinate system for the dataframe. The data is showing up directly in the center of the Atlantic Ocean (it should spread from the west coast of US through Europe.)
Is there something obvious I'm missing?