Hi all! I am having the worst time with researching my great-great-great grandfather!!! These are the facts that I have (I will put a * next to the ones I am not 100% sure of!)

1- I have found him listed at John Charles Buehrlen, Jno C. Buehelen, and *Johann Buhrlen.
2- I know that he was married atleast once in the United States to Elviria Murn (also have found her as Frances Elviria)
3- HE and Elviria had atleast two children Mary born about 1854 and Rosa Melissa born May 18,1869.
4- I know that he was born in Wuttemberg and came to the US through New Orleans on the ship *Leontine in Jan, 1850.
5- I found him in the 1870 US Census, Gasconage CO,MO at age 57, a teacher, and having property valued at $300, wife Elviria age 35, born in MO; daughter MAry age 16; Daughter Rosa age 1; and an Oscar Poeschel age 11 who was attending school. (I do not have any idea of who Oscar is)
6- Elviria was remarried in Nov 1885 to John Lewis Redden. Rosa married Andrew Redden in 1888. (Andrew was the son of John Lewis).
7- I have only ever found him in GASCONADE CO,MO, although I have looke din surrounding counties under the various spellings of the Buehrlen name.
I can find no record of death for John B., or ANY kind of record at all except for the above mentioned. Should I just not expect to find anything more? Any help that anyone can give would be greatly appreciated!
Thanks so much in advance!
Lori