There is a Jacob A Hoover listed as enlisting in Co K then B of 1st Missouri State Militia Cavalry on Mar 1 1862 at Gallatin MO aged 19 Musterd Out Feb 12, 1865 St. Louis MO.
There is also a Jacob A. Hoover aged 20 in the 40th OVI so we have our work cut out. What was the name of his wife?
John R.