Angus McKay was born to Angus and Margaret Campbell McKay on January 13, 1832, in Ontario, Canada and is the great-grandfather of Ibbie Switzer. In 1860 McKay traveled from Ontario to the east coast of the United States, from which he sailed via what was then the Panama Isthmus to San Francisco. He then took a stagecoach to the Walla Walla Valley. Upon arrival, he established a freighting business supplying pack trains with goods.

He married Mrs. Mary Ann Winship Née Hunter in 1866, and the couple had seven children, three of whom, March, Angus Jr., and Bessie, survived into adulthood, along with Mary Ann’s two children born of her first marriage, William and Lillian. The couple settled on a homestead near Russell Creek, where they lived for 61 years. While living in Walla Walla, McKay served 58 years as Justice of the Peace and several years as the chairman of the county republican party. He was also a founding member of the local Masonic Lodge and a lifelong member of the Presbyterian church. He died in Walla Walla on March 7, 1928 of pneumonia, following hospitalization for a broken hip.