According to Edward August Aussieker's marriage record (he was a son of Dietrich and Charlotte), his father's name is John Dietrich Aussieker- or rather, Johann Dietrich, that might help you more
Dietrich and Charlotte married 12/6/1858 in Whiteside County, ILL, and his name was Diedrick Aussicker
1860 census, Cedar Rapids, Linn, Iowa Frederick Wirth 32 barber Bavaria Minna Wirth 20 Mecklenburg Frederick Kroichk 15 Mecklenburg D Aussiker 29 cigar maker Hanover Charlotte Aussiker 26 Hanover Charles Aussiker 9/12 IL since they are living in the same house, I wonder if there is a family connection
From the 1900 census, Charlotte says that she immigrated in 1858, she had 12 children, 6 living
U.S., Civil War Draft Registrations Records, 1863-1865 about D Aussicker Name: D Aussicker Residence: Cedar Rapids, Linn, Iowa Class: 1 Congressional District: 2nd Age on 1 July 1863: 32 Estimated Birth Year: abt 1831 Race: White Marital Status: Married Place of Birth: Germany cigar maker naturalized citizen
He is on the Linn County IRS tax lists in 1863
1870 census, Cedar Rapids, Linn, IA Diedrich Ausicker 39 Hanover Charlotte Ausicker 36 Mecklenburg Chas Ausicker 10 IL Annie Ausicker 9 Mary Ausicker 7 Augusta Ausicker 5 Willie Ausicker 2 Edward Ausicker 4/12 all others b IA
A lot of German records were destroyed in the World Wars, I don't know if you'll ever find where they were born.