HIRAM FOSTER - WHERE ARE YOU??

Hi everyone, my brickwall is Hiram Foster b. 1810-11 KY he married Sarah Ann Roark in 1830 Pike Cty, IL. Hiram and Sarah had 13 kids and lived in KY, IL, MO, IA. Iowa is where I lose Hiram. One of Sarah boys was killed in the battle of Pea Ridge so she applied for his pension. She stated that Hiram abandoned them Jan. 29th 1859 and didn't know if he was even alive. Hiram's brother concured with that statement. She was living in Clarke Cty, Iowa at the time.
I found all of them in the 1850 Census but just she and the kids in the 1860 census. She stays around Iowa for about 10 years and then they homestead in Nebraska and that is where she buried. I have tried every avenue I can think of on the internet. The old family story is that he left with the hired girl and wasn't seen again.. You would think there is another family out there somewhere.
Sure hope someone can help solve this. I have been working on this for over 20 years.
Actually, there were two brothers of Hiram's that stated the same thing, John C. Foster and Francis M. Foster, that he abandoned his wife and kids and that the son that died was the sole support of mom 8 years prior to the war.(makes you wonder what Hiram did for a living) They signed this 2 day of march 1870, they are both from Clarke Cty, Iowa. This was pension #141,994. She did finally receive it and got $12 or 15 a month until she died. This was signed at the clerk of the district court in IA. This was just before she was granted the pension but she applied more than once. One thing his brother stated in one of his statements was that Hiram has continued to remain abroad since & had failed to care for his wife and family. What do you think the word abroad would mean during this time in history.
The wife and kids end up in NE in 1870. Her oldest son mentioned that he help build his WIDOWED mother the first frame house in the area. (early 1870's) Her tombstone list her husband and the kids (wasn't that nice) but he is not buried there.
Ancestry, they all copied each other, has his death date and where buried, If they would have looked more closely they would have seen it was the same as his son.
There are two HIrams from Iowa in the CW but they are to young and Iowa hasn't got all of there cemeteries up yet...
I know this is long but sure can use some help.
Thanks, Bernie Foster-McCall