Finding a grave site with a family tombstone and a military tombstone can provide a wealth of information.  Knowing a family member served in the military can open the door to various other record groups (pension records, military history and awards).  Surprises can arise when the dates on the tombstone do not match those of actual records.

I was researching a military record to find out that the date of birth on the enlistment papers did not match those of real birth date.  After a bit of checking, it was discovered that the person falsified their birth date to enlist with his brothers.

Using the regiment information on the tombstone, I was able to discover more information about a brickwall problem I was having with one of the brothers.

Not all military tombstone are full stone, but just a marker with a symbol representing the war the ancestor served in.  Your Guide to Cemetery Research by Sharon DeBartolo Carmack has more information on military tombstones and markers.