Indexed as John W. in 1920 Census. Unmarried, living with his mother, unmarried brother James and adopted 11 year old Christopher in Boston.

1923 directory has him living at 19 Mapes Street, a signalman.
1926 at 32 Mapes Street with his brother James.

Living with his mother in 1930 census, renting at 309 Adams Street, Dorchester.

name: John William Cassidy
birth date: 18 Apr 1890
birthplace: Boston, Suffolk, Massachusetts
father's name: Michael W. Cassidy
mother's name: Ellen