Samuel A. McWilliams was born in Kansas on March 2, 1886, the son of Fletcher and Mary (Garrett) McWilliams. He grew up on his parents' farm in Washington County, Kansas. In 1911 he came to Montana to work on the Flathead and Huntley irrigation projects. He remained in Montana and worked on the Milk River Project from 1914 to 1916. By 1930 he was living in Los Angeles, California, and was married to Ivah, and had a twin son and daughter, Gordon and Mary. He died in Los Angeles on January 30, 1962.
From the description of Samuel A. McWilliams papers, 1910-1930, (bulk 1910-1916) . (Montana Historical Society Library). WorldCat record id: 417699273