As soon as you create your own original work, you own the copyright to it.
This is automatic and does not require anything extra from you.
After your work has been sent to ProQuest, you are still the copyright holder.
More information about copyright and your work can be found in the video below, from the University of Illinois:
When you finish your work, a copy will be kept at The Iowa State University Digital Repository (ISU DR). The DR is open access and free for anyone in the world to see, allowing your work to reach a wider audience.
Want to share more research in the DR? We want the world to be able to access, read, and cite your research! For more information about how the DR works, see the information below.
In addition to depositing your work in the ISU Digital Repository, a copy of your thesis will also be added to ProQuest's Dissertations and Theses database. Unlike, the DR, ProQuest's database is paid for by subscription and will be accessible only to those with log in information. If you have questions about copyright related to ProQuest, please see the PDF, Copyright and Your Dissertation or Thesis below. Still have questions? Contact the Graduate College at email@example.com.
Copyright is immediate upon the creation of a work. In other words, the moment that you create something, you have complete control over the copyright of your work. However, if you would like to have a more official record of your copyright ownership, you may choose to register your copyright. The Graduate College suggests this option if you plan on using your work to: