Miltary pensions, especially if the widow survived and claimed her pension, may provide information about more than just the veteran and his widow. Relatives might have had to testify to the marriage of the veteran and his wife, their residences, their children and other information in an attempt to document the pension. These documents are more detailed if the widow cannot find her marriage certificate or the courthouse burned. Relatives who were present at the marriage or who knew of the couple's marriage might have testified. Wonderful records these are.
My ancestor's Civil War pension provided information about the wife's family, including her siblings. She also indicated who was at her 1867 wedding and the sister-in-law who was present at the birth of one of her children.