Answer: John McArthur.
Born in Scotland in 1823, John McArthur immigrated to the United States when he was 10 years old. After an apprenticeship with a local carpenter, he took classes in design and drawing at the Franklin Institute in Philadelphia. At age 25, McArthur designed his first building, the House of Refuge, which was once located near the Eastern State Penitentiary. Other early works include the Tenth Presbyterian Church (1854), the Wagner Free Institute of Science (1859), and the Public Ledger Building (1866).
In 1869, McArthur won a design competition to plan a new city hall building in Philadelphia to be constructed on the site of William Penn’s original Centre Square at the intersection of Broad and Market Streets. Other proposed plans for City Hall are pictured at left. Completed in 1901, the Second Empire style building was adorned with over 200 sculptures and topped with the famous bronze statue of William Penn designed by Alexander Milne Calder (1846-1923). Originally designed to be the tallest man-made structure in the world, City Hall never achieved that honor; the Eiffel Tower won in 1889. However, it remained the tallest building in Philadelphia for a number of decades. There existed a “gentleman’s agreement” within the city that prevented the construction of any buildings beyond the top of William Penn’s statue. In the late 1980s, the One Liberty Place skyscraper became the tallest building in Philadelphia.