Hi,

To give people a search starting point it's always good to post where the family can be found - it may give clues:

1920:

Name: Oscar Warwick
Home in 1920: Masseys, Kent, Maryland
Age: 21 years
Estimated Birth Year: abt 1899
Birthplace: Maryland
Relation to Head of House: Head
Spouse's name: Edna
Father's Birth Place: Maryland
Mother's Birth Place: Maryland
Marital Status: Married
Race: Black
Sex: Male

Oscar Warwick 21
Edna Warwick 21
Lillian Warwick 6
Jane Warwick 3 0/12
Matilda Warwick 3/12

Two John Harris listing next to this family - looks like one may be father-in-law (listed as widowed) , the other may be Edna's brother.
Have you tracked them in 1930?

In 1930 Oscar seems to be living not with wife and children - working in Philadelphia, though still listed as married (if this is your Oscar):

Name: Oscar Warrick
Home in 1930: Philadelphia, Philadelphia, Pennsylvania
Age: 33
Estimated Birth Year: abt 1897
Birthplace: Maryland
Relation to Head of House: Head
Race: Negro
Household Members: Name Age
Oscar Warrick 33
John Hynson 24
Jessie Hynson 22
Hattie Hynson

while Edna seems to be listed as widowed - if this is your Edna:

Name: Edna Brinkley
Home in 1930: Election District 1, Kent, Maryland
Age: 32
Estimated Birth Year: abt 1898
Birthplace: Maryland
Relation to Head of House: Lodger
Race: Negro

Household Members: Name Age
William Thompson 66
Mary E Thompson 62
William Thompson 38
John Thompson 36
Edna Brinkley 32

on same page there are some Warwicks - relatives?

Since the children are missing - she may have given them up for adoption or boarded them somewhere - I don't see them listed in Kent under Brinkley or Warrick but do see some other listings that are possibles - using surname Harris.

Can you tell us what else you know about this family?

Denise