[1] He was the eldest son of Lewis Linn McArthur, who served on the Oregon Supreme Court, and his wife, the former Harriet K.

[2] Clifton's only brother was Lewis A. McArthur, who would write the first edition of the Oregon Geographic Names.

[2] Clifton attended the public schools at Rickreall, and the Bishop Scott Academy in Portland.

McArthur then engaged in agricultural pursuits near Rickreall from 1903 to 1906 and studied the law in order to become a lawyer.

McArthur resumed the practice of his profession and his former business activities in Portland, Oregon, where he died December 9, 1923, following what was described as a "supposedly routine sinus operation".