I am running Wordpress 4.2.1, with CiviCRM 4.5.6. Everything works for my fresh install of CiviCRM. 

Now, I am chair of a political organization, and I got the old data for my county from an ex-member who ran CiviCRM under Drupal, but I don't know what version of CiviCRM he used a few years back (I think it was around 2011). I have imported the data into mysql as dbname "civicrm\_original" and the current running config is "civicrm".

I tried to swap out the data connection string to use the "civicrm\_original" database then ran the command:
`http://<your_wordpress_home>wp-admin/admin.php?page=CiviCRM&q=civicrm/upgrade&reset=1`

but then CiviCRM wouldn't run and it had errors like crazy, like fields not in tables and other tables not existing. So now i switched back the dataconnection to "civicrm" and we are running again, just not with all the old data.

1) how can I find out what version that database was?
2) how can I update the imported database to work with my current config?

I would be willing to update to the latest version of CiviCRM if need be. or, would it be easier to copy the data over to the new database? I know the contacts table has new fields that aren't in my "original" db.