I am working on importing XY data for bus stops in a transit system in Southern Washington and creating a buffer to identify population figures for some analysis. I was successful in selecting the Projected Coordinate System NAD_1983_StatePlane_Washington_South_FIPS_4602 in the XY data import window, however, as soon as I included the census file (with the same projected coordinate system), the shapes are about 200 miles apart from each other when they should overlap. Any suggestions on how I might be able to fix this is greatly appreciated.
You need to specify the appropriate coordinate system for each file - ArcMap will reproject them into the Data Frame's coordinate system on-the-fly. If they both claim to be in NAD_1983_StatePlane_Washington_South_FIPS_4602 and they don't line up, one of them is lying.
I made sure to specify the same coordinate system for each file, but still no luck. Do you think it has something to do with the XY data itself? It seems to be working fine, so I am not sure how to fix the issue.
Also, I noticed that as soon as I set the coordinate system of the problematic point shapefile to Geographic NAD 1983, it overlaps correctly with the shapefile set to the NAD_1983_StatePlane_Washington_South_FIPS_4602 coordinate system, however, the buffers are incorrect: the point buffers are showing up more live ovals (with incorrect distances associated) than circles. Maybe this might help diagnose the problem.
To be clear, your files don't have to have the SAME coordinate system, each file must have the PROPER coordinate system (whether they're the same or different from each other).
Your buffers look funny because Geographic NAD 1983 is not a projected coordinate system (it's geographic, like lat/long). Once you figure out the proper coordinate system(s) for your files, Project to a projected coordinate system, then buffer.