Dear Ms. Phaup,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located Case Files of Mexican War Pension Applications in the Records of the Department of Veterans Affairs (Record Group 15). While portions of this series have been digitized and may be viewed online, the file for John Jordan Phaup is not available online. To order pension records that have not already been digitized, please fill out a NATF Form 85 and mail the completed forms to the address listed on the form. You also may place your order online using eservices.archives.gov. For more information see Requesting Copies of Older (pre-WWI) Military Service Records
Please note that the National Archives and Records Administration (NARA) has suspended reproduction and digitization services until further notice due to COVID-19. Orders will not be serviced until operations can resume safely. Once operations resume, document reproduction requests will be filled in the order in which they were received. We apologize for any inconvenience.
We hope this is helpful. Best of luck with your family research!