You can build a simple Donations Report by following these steps:
  1. Navigate to the Reports tab
  2. Click New Report
  3. Select the Donations folder, then Donations
  4. Click Create
  5. In the Date Field, set the Range to Previous CY
  6. Click "Add" to create a new Filter
  7. From the drop down menu, choose Primary Campaign Source
  8. Leave the next selection as "equals"
  9. In the 3rd field, type in the campaign name
  10. Click Ok
  11. Click Run Report

You've now created a report to run on all donations made to the campaign last year.