Henry Squarebriggs Mackay

Personal Data

Henry Squarebriggs McKay (Mackay) was born on September 10, 1860 or 1861, in Kinloch, Middle Ohio, Shelburne, Nova Scotia, the son of James McKay (MacKay) and his wife, Mary Ann Squarebriggs (daughter of Henry Squarebriggs).

He married on November 3, 1886, in Shelburne, Nova Scotia, to Robena (Robina/Ruby) MacKay (b. 19Aug1859 in Shelburne; d. 15Jun1948 in Orange Co. CA), daughter of Robert MacKay and his wife, Rosanna Deinstadt.  Henry and Robena MacKay were second cousins.

Henry MacKay died on October 9, 1948, in Orange County, California.


Henry MacKay was educated in Canada. In about 1881, he entered the offices of Thomas William Silloway, known for his work in designing churches throughout New England. In about 1883, the formed a partnership, Silloway and McKay, which continued until about 1886.  McKay then practiced alone until 1888, when he took his former draftsman, Frank Warren Smith, into partnership, forming the firm of McKay and Smith.

Henry McKay’s work included the First Baptist Church in Malden; Prospect Congregational Church in Somerville; the Charles River Baptist Church in Cambridge; the Dearborn Street Baptist Church in Roxbury; and the Amherst Town Hall.

McKay and Smith designed The Abbotsford at 184-188 Commonwealth, in which both Henry McKay and Frank Smith (and Smith’s mother, Jane (Ross) Smith Palmer) had ownership interests. McKay and Smith dissolved in about 1892 and Frank Smith became a sole practictitioner.

In 1892, Henry McKay changed the spelling of his surname to Mackay and formed a new partnership with Charles Blanchard Dunham, who had been a draftsman in his office, establishing the firm of Mackay and Dunham.

In mid-1895, Charles Dunham went to Europe to continue his architectural studies, resuming his practice at Mackay and Dunham upon his return. The firm continued until 1899, after which Charles Dunham continued as a sole practitioner.

Mackay and Dunham designed apartment houses, hotels, and commercial buildings, among them The Chesterfield at 371 Commonwealth (1892), The Ericson at 373 Commonwealth (1892), The Empire at 333 Commonwealth (1895), The Tuileries at 270 Commonwealth (1896), and the Blackstone Block on North Street (1899).

In addition to his architecture practice, Henry Mackay was president of the Vermont Granite Company in Barre, Vermont.

He also owned two of the apartment hotels that Mackay and Dunham had designed: the Empire and The Tuileries. To finance their construction, he entered into multiple mortgages on both properties. In December of 1899, the mortgages were foreclosed. He and his family moved to the West in February of 1899 and he was declared bankrupt in April of 1899.

Henry Mackay and his family remained in the west, where he became a mine engineer, promoter, and investor, referred to as a “prominent mining man from Boston” in a September 29, 1900, article in the Mohave County Miner (Mineral Park, Arizona). He developed mines in the southwest and in Mexico.

In June of 1900, at the time of the US Census, the Mackays were living in Denver and by 1903 they were living in Ocean Park, California. By 1908, they had moved to Belvedere, California, and he was an architect with Woodruff Company in San Francisco. By 1910, he had moved south again, was living in Riverside, and had established the Mackay Copper Process Company.

Back Bay Work

1889 184 Commonwealth [McKay and Smith]
1890 186-188 Commonwealth [McKay and Smith]
1892 371 Commonwealth (61 Massachusetts) [Mackay and Dunham]
1892 373 Commonwealth [Mackay and Dunham]
1895 333 Commonwealth [Mackay and Dunham]
1896 270 Commonwealth [Mackay and Dunham]