Okay we have another Peter to puzzle over, not sure if it is a first or middle name:

Peter was born about 1839 in Indiana per 1850 Census in 'District 4, Scott, Iowa, USA'

Was living with Emma Knapp Moore (George Washington Moore and their family), she is the daughter of Daniel Knapp and Sala Myra 'Sally' Wilson (Correct name from family bible)

This makes me think Peter is the missing son (still missing a daughter) from the 1840 census in Muscatine, Iowa Territory, USA where Emma's family is listed under Daniel Knapp.

Anybody know him or the missing sister born 1835-39??