When I upload it as a hosted file - I get an error - for any of the files I download from here - but not other shapefile data.
I can’t be certain what the problem is. However, my hunch is that the problem is associated with the maximum file size allowed in the online version of ArcGIS. The file size limit on shapefiles uploaded to ArcGIS Online is 10 megabytes. Unfortunately, almost all IPUMS shapefiles are much bigger than this limit.