Dear Ms. Bodenburg,
Thank you for posting your request on History Hub!
There are several types of records available that document individual soldiers that served during the War of 1812. Some types typically have ages, and some typically do not.
The great majority of soldiers who served during the War of 1812 were volunteers, or members of state militia who were federalized for portions of the war period. We searched the National Archives Catalog and located Carded Records Showing Military Service of Soldiers Who Fought in Volunteer Organizations During the War of 1812 (aka Compiled Military Service Records for the War of 1812) in the Records of the Adjutant General's Office (Record Group 94) These records do not ordinarily list the ages or birthdates of the soldiers. Some of these records have been digitized and can be viewed online through the Catalog by clicking the blue “Search within this series” button.
We also located Enlistment Papers, 1798 - 10/31/1912 and Registers of Enlistments in the United States Army, 1798 - 1914 in Record Group 94 which includes records concerning those who served in the Regular Army as full-time professional soldiers. These records list age.
We also located Post Revolutionary War Papers, 1784 - 1815 in Record Group 94 that includes records relating to the discharge of Regular Army soldiers. These records often give the age of the soldiers at time of discharge. Please see our topic page War of 1812 Discharge Certificates for more information about these records.
Finally, we located the War of 1812 Pension and Bounty Land Warrant Application Files in the Records of the Department of Veterans Affairs (Record Group 15). These records often include the ages of applicants. Some of these records have been digitized and can be viewed online through the Catalog by clicking the blue “Search within this series” button.
To order copies of War of 1812 service and pension records of specific soldiers which are not already available online, please fill out a NATF Form 86 and mail it to Archival Operations Washington D.C., Form 86 – Military, National Archives and Records Administration, 700 Pennsylvania Avenue NW, Washington, DC 20408-0001. You also may place your order online using eservices.archives.gov. For more information, please see Requesting Copies of Older (pre-WWI) Military Service Records and/or email the National Archives at Washington, DC - Textual Reference (RDT1) via firstname.lastname@example.org for questions about these records.
Finally, some state archives have additional records and other resources about soldiers from their state, particularly those affiliated with volunteer and militia units. For example, see the Library of Virginia's guide to Soldiers of the War of 1812.
For additional information, please review the following.
We hope this is helpful. Best of luck with your research!