John's first 2 children were Charles, born May 1855, and Phebe, born 1857. I assumed that they belonged to John and his first wife.
However...I cannot locate John with the 2 children in the 1860 census! There are a couple of faint possibilities...one being a family with very similar names living in a resort town ["Mexico"?], upstate New York.
Then I came across the statement in the "Brooklyn Daily Eagle", that John Hempstead, nephew of the notorious Emma Augusta [Hempstead] Cunningham, in 1857 languished in the Suffolk County jail on charges of bigamy!
John's son Charles turned 2 years old in 1857; his daughter Phebe was just born that year. Did he marry Mary Walton in 1857, while still married to the first wife?
It appears that John's first 2 children considered Mary Walton their mother; I believe her name appears on the death certificate of son Charles Hempstead, and appears so in other people's genealogies. I am not certain that is correct; just have to prove it, one way or the other!
- check Bklyn church records for John's first marriage
- try to obtain court records of bigamy charge
[unavailable per correspondence with Riverhead]
- try to find marriage record, John to Mary Walton
Mary for husband John's military service: marriage
date was 5 July 1856. Son Charles was born 1 May
1855, so probably son of John's first wife - who was
still married to John when he married Mary, if his 1857
arrest for bigamy was warranted.
UPDATE: at 1850 Mary was a child living at home with her parents. At 1860, her name and the name of the 2 children enumerated with her should have been Hempstead. As to Charles' age , it should have been 4 or 5; his birthdate was 1 May 1855 - depending on the effective census date, he could have been either age. The age written in the census was probably an error.