John McArthur Jr. was born in Bladenock, Scotland, on 13 May 1823,[1] and came to the United States with his family when he was ten years old.
Much of his mature style was characterized by Italianate and Second Empire forms and several of his best-known buildings feature mansard roofs, which he helped to introduce and popularize in the United States.
Later, this was surpassed by the tower of City Hall (1874–1901), whose 548 feet (167 meters) made it the tallest occupied building in the world when completed.
Until the late 20th century, an unwritten agreement among Philadelphia architects kept all buildings shorter than the top of the statue of William Penn atop McArthur's tower.
[citation needed] A Presbyterian and a member of Tenth Church, McArthur was married to Matilda Prevost; they had two sons and two daughters.