No official notifications sent as the miiltary had no record of next of kin. As a result wives wondered about being widows or not. The wait could be months or even years, with no real answer.

I'm not sure when notifications began - WWII may have been the first American conflict in which this became official policy.

Sommersby (Jodie Foster, Richard Geer), filmed in and around Lexington VA, is based on this situation (a Confederate soldier's wife suspecting she may be a widow but not knowing one way or the other).