The occupation "fruiterer" is form the Canada Census; the City Directory says "fruit dealer" which seems to lack the distinction of "fruiterer"! William was somewhat younger than the other immigrant Slattery's, but there are some intriguing clues that suggest that he may have been related to the By-Ward Slatterys.

William was born about 1843 in Ireland, son of John Slattery and Bridget Hickey. He married Bridget Trimble in 1866 at Notre Dame Basilica. From the records of St. Joseph's Church, Ottawa, and from the census data, it is established that William's wife was born in 1851.

William appeared first in 1871 in the Ottawa City Directory, as a fruit dealer, working and living on Clarence St. in By-Ward, the street where William of By-Ward and his brother Myles were then living. He moved several times in the Lower Town area until his death in 1892. William and Bridget had five children, of whom Edward, born in 1871, is of special interest to this story.

In 1888, Edward, then 17, was first reported working as a clerk at the Wellington Ward Market for Thompson & slattery, the first of the expansion locations of William and his son Bernard Slattery. After his father's death, his mother evidently moved to Main Street, where William and Bernard already had homes. Edward lived with his mother and younger children until at least 1902, while still working for Bernard Slattery. It is possibly more than a coincidence that William the fruit-dealer and his family lived always close to William and/or Bernard, and continued so until at least 1902 (I haven't researched past this date).