The Union Arcade was one of three buildings financed by coke and steel magnate Henry Clay Frick in the Grant Street area. The other building projects included the Frick Building (built 1901-1902 at the corner of Grant Street and Forbes Avenue) and the William Penn Hotel (built 1914-1916). The land purchased by Frick from the Catholic Diocese in 1901 for the Union Arcade was the original site of St. Paul's Cathedral. It was widely rumored that Frick desired this plot of land in particular because of its strategic position. The combination of his three buildings would overshadow rival Andrew Carnegie's headquarters in the Carnegie Building on Fifth Avenue. Within a few years, Frick began working with local architect Fredrick John Osterling on building plans for the Union Arcade. With the aid of the George A. Fuller Company as the general contractor, construction began in 1915 on the Flemish-Gothic style building, which was to feature such architectural accents as decorative terra-cotta, skylights, and an impressive Tiffany stained-glass dome over a large central rotunda. Pittsburghers hailed the building's style and were especially proud that Osterling, the esteemed Pittsburgh native who had also designed the Arrott Building, the Times Building, and the County Mortuary, was chosen as architect. Despite opening in April 1917, the Union Arcade was far from completed and seriously behind schedule. Actual completion of the building did not occur until the fall of 1917. The first four floors of the Union Arcade were designed to house 240 retail shops with the upper seven floors providing enough space for approximately 700 offices. However, by 1921, the booming retail market in Pittsburgh became centered a few blocks from the Union Arcade. As a result of lagging retail sales, Frick sold the building to the Union Trust Company. In the following year, major changes were put into place filling in the retail space so that the entire building would be available for offices. The building's name was consequently changed to the Union Trust Building. Frick deemed that the work Osterling had done was unsatisfactory and refused to pay for his services. This seemed an odd move for Frick considering he had worked with Osterling previously; the architect had helped with a major renovation to Frick's home a few years prior to work on the Union Arcade. Nonetheless, Osterling brought a court case against Frick in 1921, which would become one of the longest running cases to date in Pittsburgh. After much debate, Osterling won the case. The building changed hands once more in 1984 when it was sold to DeBartlo Holdings. It was also around this time when the city found a renewed interest in the building. Mellon Financial moved in and the building was renamed Union Trust/Two Mellon Center. Furthermore, the 1980s saw the beginnings of numerous restoration projects on the structure designed to fix the continual problem of water damage that the building had experienced since its opening in 1917. While visually spectacular, the four-story terra-cotta Mansard roof which tops the Union Trust Building had never been properly insulated from the elements. Many small, cosmetic construction projects took place, but it was not until 1999 that a full-scale restoration effort began to properly re-build the roof. The Union Arcade Building has also sparked much rumor and local legend. Since the land originally was the site of a cathedral, it has been alleged that Frick promised the local diocese that a chapel would be included in the design of the Union Arcade to maintain some element of religion on the site. What seems to confirm this rumor is the existence of a structure that resembles a small chapel on the top of the building that can be seen from street level. While it was known that the "chapel" simply housed mechanical components for the building and storage, rumors persisted for decades that church services were held on the roof of the Union Trust Building.
From the description of Union Arcade Building photograph collection, 1915-1916. (University of Pittsburgh). WorldCat record id: 608549007