In U.S. Federal Census records for 1900, 1910, and 1920, the family is easily found in Winnetka Village, New Trier Township, Cook County, Illinois.
In 1920, they are living at 200 Chestnut Street, with Florence M. Greely as Head of household.
|Database online. Year: 1920; Census Place: New Trier, Cook, Illinois; Roll: T625_361; Page: 15A; Enumeration District: 131; Record for Florence Greely.|
Lines 28-36 list their household. Although Lowell is listed as brother-in-law, and Ethel M. is listed as sister-in-law, the relationship is a little more complicated. Florence is actually the widow of Ethel's half-brother, Frederick Greeley, who died in 1912. Lowell and Ethel's children are Townsend (age 19), Elizabeth (age 16), and Ruth (age 12). All three children attended school during the previous school year. Lowell's occupation is Manufacturer in the Machinery industry.
In reviewing this record, I notice that the next family, on Birch Street, is Samuel A. Greeley, a civil engineer, with children Sewall and Frederic. A quick check in my tree tells me that Samuel is a son of Florence and Frederick and I have not linked him to this census record, nor entered his wife and children into Family Tree Maker. Better do that now, before I forget...
Lowell was born in Maine and Ethel was born in Illinois.