Who is Alexander I Ingalls dob 9/5/1853

Question

I am trying to track down the line of Elvin Othie Ingalls who died in Vernon Parish. I have gone so far as to find his grandfather, Alexander I Ingalls, but am stuck with the 1870 census. At that time he was living with a Charles M Ingalls who I assumed to be a brother. But while I have found a decent amount of info on Charles M, it doesn't seem that there is any other connection. Oh, at the time of the census Alex was 16 and Charles M was 25. Any insight appreciated.