It could be this family, note spouse of Carl is 'Martha' not Mary in Census, but maybe the siblings will ring a bell. (from familysearch.org)
In that 1930 Census Jack Behr listed as b. abt 1910 and a separate birth record in June 2, 1909 - shows son of Carl and Mary (Findklestein) Bahr, might be the same individual.
Illinois, Cook County Birth Registers
Name:Bahr Male
Birth Date: 02 Jun 1909
Father's Name: Carl Bahr
Mother's Name: Mary Finkelstein
Film Number: 1315046
Digital Folder Number: 4394342
Image Number: 00836
Reference Number: p. 39, Ln 1914
United States Census, 1930
Event Place: hicago (Districts 0751-1000), Cook, Illinois
Household Gender/Age
Parent Carl Behr M//55 abt 1875 POL/POL/POL immig 1905
Martha Behr F/47 abt 1883 POL/POL/POL
Joe Behr M/21
Jack Behr M/20
Irving Behr M/19
Lester Behr M/17
Isreal Behr M/15
David Behr M/12
Hayner Behr M/11 (Hyman on birth record)
Idell Behr F/8
Son in aw: Morris Handelman M/26
Rose Handelman F F/25