The house at 202 Widder Street East was built about 1886 by Daniel and Charlotte McLaren and first occupied by Leonard Harstone.

Leonard Harstone was the son of Robert Harstone, from Argyllshire, Scotland, and Jane Hopper. Robert had come to Canada as a young man and established a grocery business in Baltimore, a small community north of Cobourg. The Harstones arrived in St. Marys about 1860 where Robert set up as a merchant. Leonard, born in Baltimore in 1854, received a good education, attending Upper Canada College in Toronto. He taught school for a few years but later studied law at the University of Toronto, returning to St. Marys to practise.
About 1886 Leonard, with his widowed mother, moved into the new house at 202 Widder Street East, at the corner of Peel Street North. The property was owned by Charlotte McLaren. Charlotte lived nearby at 140 Peel Street North with her husband Daniel, a retired farmer. The McLarens appear to have built the house, almost certainly a one-storey Ontario Cottage, as a rental property. Daniel died soon after in 1888.
Leonard was appointed clerk of the town in 1890. He had a convenient arrangement that allowed him to use an office in the town hall not only for his duties as clerk but also as a base for his private law practice. He later became the town solicitor.

Leonard married in 1898 at age 44. His bride, Drucilla Beatrice Maude Windsor of Toronto, was 23 years younger. When their only child, Robert, was born in 1899, the family moved to a new house at 129 Water Street North. They also rented this house but in 1913 they had an opportunity to purchase the grander, more spacious house to the north and made the move to 137 Water Street North.
Leonard Harstone died there in January 1932 at age 78. According to his obituary in the St. Marys Journal Argus.

Mr. Harstone was a fine gentleman of the old school. He was kindly and considerate to young and old and those who knew him down through the years had reason to regard him as a man to love and admire. In connection with the practice of his profession he commanded in an exceptional way the confidence and unqualified trust of the public.

Beatrice lived on with her son, Robert H. Harstone, also a lawyer, until her death in 1957. She is buried with Leonard in St. Marys Cemetery.

In 1899, after the Harstones left 202 Widder St. E., Charlotte McLaren moved into the house herself. She died in 1902 and the house was sold to James Davidson who lived there with his wife Margaret.

In 1910, when the property was owned by the Coupland family, there was a sudden jump in its assessed value. This indicates major improvements, likely the addition of the current second storey to the original cottage.