Background
Arthur Trautwein Henrici was born on March 31, 1889 in Economy (now Ambridge), Pennsylvania, United States. He was the youngest of five children, four of them boys, of Jacob Frederick and Viola (Irons) Henrici. Though his mother's family was Scottish, he was mostly of German descent.
The Henricis, originally religious dissenters from the Piedmont province of Italy, had settled in the Rhenish Palatinate, from which Arthur's great-uncle, Jacob Henrici, led a family group in 1823 to the United States; there he joined the Harmony Society of George Rapp, a communitarian settlement at Economy, of which he became the leader after Rapp's death. Henrici's father, however, was not a member of the Society, and the boy grew up in Pittsburgh, where his father was a bookseller and writer for newspapers and magazines and a member of the Unitarian Church.