Hi mimishell! Welcome to the forum...
Can I ask a few questions of you first?
You mention that you think Ralph arrived in 1900 at age 11. Does this mean that you are certain that his
year of birth is about 1889?
Were he and Filomena married in US?
In looking for US records (so we can work backwards to possible origin of birth) - I have
Ralph Deleppo residing in Waterbury, Connecticut with wife Grace in 1940 - Would this be your GF?
If the birth date of 1889 is correct...
here is another POSSIBILITY for the arrival for Ralph/Raffaele in 1892 at age 3 
Notice the spelling of the surname.
I will try to find an image of the manifest to identify with whom he is traveling.
Given Name:
RaffSurname:
DellioppoLast Place of Residence:
Event Date:
15 Jun 1892Age: 3y 2mNationality: Italy
Departure Port: Naples
Arrival Port: New York
Gender: Male
Marital Status:
Citizenship Status:
Ship Name: California
Have you seen this WWII Draft Registration Card? Lists his name as
Frank Ralph Deleppo. Could be that his given name is Francesco/Frank, and Ralph/Raffaele was his middle name...
https://familysearch.org/pal:/MM9.3.1/T ... 1140593490Frank Ralph Deleppo, "United States, World War II Draft Registration Cards, 1942"Name: Frank Ralph Deleppo
Event Type: Draft Registration
Event Date: 1942
Event Place: Waterbury, New Haven, Connecticut
Gender: Male
Birth Date: 05 Oct 1888Affiliate Publication Title: World War II Draft Cards (4th Registration) for the State of Connecticut
Affiliate Publication Number: M1962
Affiliate ARC Identifier: 2555449
GS Film number: 2283207
Digital Folder Number: 004135818
Image Number: 01566
You stated...
I think my grandfather, Ralph Deleppo may have actually been, Raffaele DelCioppo who arrived in America via Ellis Island when he was 11 in 1900. If this is correct his parents were Felice and Michelina DelCioppo who listed their last place of residence as Campobapo(Campbasso?). I would like any information on the family history.
In the
1930 US Census, in Waterbury, Connecticut, Ralph is a widow with 3 sons and
his mother, Michellina Delleppo, age 65, living with him...
He also gives his immigration year as 1897, as does his mother.
Ralph Delleppo, "United States Census, 1930"
Name:
Ralph DelleppoEvent Type: Census
Event Date: 1930
Event Place: Waterbury, New Haven, Connecticut
Gender: Male
Age: 42
Marital Status:
WidowedRace: White
Birthplace: Italy
Birth Year (Estimated): 1888Immigration Year: 1897Relationship to Head of Household: Head
Father's Birthplace: Italy
Mother's Birthplace: Italy
District: 0212
Household ID: 208
Sheet Number and Letter: 9A
Line Number: 9
Affiliate Publication Number: T626, roll 279
GS Film number: 2340014
Digital Folder Number: 4531883
Image Number: 00364
Household Gender Age Birthplace
Head Ralph Delleppo M 42 Italy
Son William Delleppo M 15 Connecticut
Son Phillip Delleppo M 12 Connecticut
Son Dante Delleppo M 9 Connecticut
Mother Michelina Delleppo F 65 Italy In 1917, he completed the Connecticut Military Census as FRANK DELLEPPONice physical description here, but no specific place of birth...

He is also listed on his
WWI Draft Registration as FRANK DEL CIOPPO (alias DELLEPPO)
T.