Narrowing down a date and place

So I have been trying without luck so far to find when and where my great grandparents on the Blom line. 

My great grandmother Jeanette Moes is found under her maiden name living with a different family in the 1920 US Federal Census.  In the 1930 US Federal Census she is found living with my great grandfather John A. Blom and their daughter. 

So at least I have narrowed down the decade.  Now I just need to find the date and place.