Are you looking at your imported data in table view? There's a limit to how many columns you can see at one time when in table view.
To see what fields were actually created during import, open manage | database | fields and see what fields appear there.
Bingo!! That was indeed the problem, the fields are there, just not showing in table view.
To work with your data, you have several options for seeing the other columns:
Just keep modifying the table view to see different columns of data
Create several layouts to the same table--each with different sub sets of tables
Use list view instead of table view
Consider restructuring your data so that you don't have so many fields in one record.
The data I'm using is an export from another program and is provided each day by a client. I'll probably never use some of the data that is in some of the columns but I'm hesitant to delete it just in case we ever need to look at all of the original data. I think your idea of creating layouts that are tailored to my needs and contain only the data that I need is the way I'm going to proceed.
Thank you again for your assistance, and I'm sure I'll be coming back to these forums for assistance pretty regularly.