Dear Ms. LaFata,
Thank you for posting your request on History Hub!
These indices indicate that there should be a compiled military service record for John Manasco in the record series titled Carded Records Showing Military Service of Soldiers Who Fought in Volunteer Organizations During the War of 1812 in the Records of the Adjutant General's Office (Record Group 94). There should also be a pension file and/or land bounty warrant for him in the record series titled War of 1812 Pension and Bounty Land Warrant Application Files in the Records of the Department of Veterans Affairs (Record Group 15). While some of these files in these series have been digitized, the ones for John Manasco have not yet been digitized.
To order copies of these records, please fill out a NATF Form 86 for the service record and a NATF 86 for the pension records and mail them to the addresses listed on the forms. You may wish to attach copies of the index cards to your order. You also may place your order online using eservices.archives.gov. For more information see Requesting Copies of Older (pre-WWI) Military Service Records or email National Archives at Washington, DC - Textual Reference (RDT1) at firstname.lastname@example.org.
However, please be aware that because of the current public health crises, the National Archives in Washington closed not only to researchers, but to staff. While many RDT1 staff are teleworking and can respond to email questions, the staff will be unable to fulfill any requests for reproductions of records held at this facility until conditions permit the staff to return to the building. You may still submit your request now, but please be patient as it may take some time until the staff can respond.
Finally, because he was with a Tennessee militia unit, there may be records concerning his service at the Tennessee State Library and Archives.
The Prologue article Genealogical Records of the War of 1812 provides additional information about researching individual soldiers.
We hope this information is helpful. Best of luck with your research!
Thank you for the information.