Great Great Grandfather's information

Looking for any information on my great-great grandfather. His name was Frederic Wilhelm Oertel and he would have arrived here in approximately 1861. He was born in Germany in 1836. He would have been the appropriate age for fighting so I'm curious if there are any military records for him. I can't find any immigration records for him so the arrival date is just a guess based off his death certificate. I've been searching for over 20 years for any information so anything is helpful and thanks in advance.