Did you know that the 1910 census asked if the person was a veteran of the Civil War? The third from the last column asked if the man was a “Survivor of the Union or Confederate Army or Navy.” Be careful though– not every census taker recorded this (some of my own Civil War ancestors have no notation there). And the census taker also used this column for other note taking at times.
As you can see from this picture, only one of these men has the Civil War notation. A number in the column does NOT indicate Civil War service– those are usually other notes made by the census taker. You want to look for a “UA” or “UN” for Union Army or Navy or “CA” “CN” for Confederate Army or Navy.
Now go find your ancestors in the 1910 census– see what their notation says!