Is this your family as found in the 1930 Taylorville, Christian, Illinois census?
Joe Kastelic 53 Arr US 1902 from Austria Slovenian
Mary Kastelic 48 Arr US 1904 " "
John Kastelic 20 born PA
William Kastelic 18 Born IL
Rose Kastelic 12 Born IL
Joe Kastelic 10 Born IL
1920 Lovington, Moultrie, Illinois Census Ancestry mistranscribed their info as follows
Joseph Kastellie 39 Arr 1903 NAturalized Aust "Slavish"
Mary Kastellie 36 Arr 1905 " "
Mary Kastellie 14
John Kastellie 10
Willie Kastellie 8
Rose Kastellie 2
Joe Kastellie 0
And from the 1910: Hempfield, Westmoreland, Pennsylvania All Children born PA
Joseph Kastelic 33 Arr US 1902 Aust. Slovenian
Mary Kastelic 26 Arr US 1904 " "
Mary Kastelic 5
Joseph Kastelic 3
John Kastelic 2/12
KASTELIC and KOSTELIC are relatively common names in Slovenia and neighboring Croatia and many men with this name came to America, perhaps 4 or 5 that match the DOB and immigration date range.
The original spelling is KASTELIC with a diacritical mark v over the C giving it the sound of CH
Slovenian: from a derivative of kastel ‘(small) castle’, ‘fort’ (formed with the obsolete suffix -ic instead of standard -ec), a topographic name for someone who lived in or near a castle or a fort.
Dictionary of American Family Names, Oxford University Press, ISBN 0-19-508137-4