Question

I am researching Jeremiah and Christina Bair who lived in Missouri during civil war.

Answer 1

Are they spouses? sibings?  parent and child?

Try the free search tool at familysearch.org, https://familysearch.org/

Examples below.

For:  Christina Bare/Barr/Baer/Barre/Bear: Residence MO 1850-1880 see:

https://familysearch.org/search/records/index#count=20&query=%2Bgivenname%3Achristina~%20%2Bsurname%3Abair~%20%2Bresidence_place%3AMO~%20%2Bresidence_year%3A1850-1880~

For Jeremiah or J.  Bare/Barr/Baer/Barre/Bear: Residence MO 1850-1880 see:

https://familysearch.org/search/records/index#count=20&query=%2Bgivenname%3Ajeremiah~%20%2Bsurname%3Abair~%20%2Bresidence_place%3AMO~%20%2Bresidence_year%3A1850-1880~