When Thaddeus E McHolland was born in December 1868, in Washington Township, Daviess, Indiana, United States, his father, Isaac Espy Mc Holland, was 27 and his mother, Amanda Johnson, was 22. He married Minnie Louise Martin on 8 February 1899, in Portland, Multnomah, Oregon, United States. They were the parents of at least 2 daughters. He lived in Cowlitz, Washington Territory, United States in 1880 and Saint Johns, Multnomah, Oregon, United States in 1900. He died on 3 July 1935, in Portland, Multnomah, Oregon, United States, at the age of 66, and was buried in Portland, Multnomah, Oregon, United States.