Another interesting find at the National Archives today. Alexander Culnan enlisted in the US Army in 1819, when he was 15 years old. Since he was a minor, his father Charles also signed off on this document, allowing him to join the army for a five year enlistment.
Keep in mind that this was in 1819. Finding documents that link fathers and sons together are difficult to find in this time period. If you were related to this family, this could be that missing link you had been looking for.
If your ancestor enlisted in the US Army during peace time, they are likely to have enlistment papers on file at the National Archives. Order your ancestor's enlistment papers here!