Question: When was one of the tallest structure built which is taller than The Milwaukee City Hall and is the seat of government for the city of Philadelphia?
Context: Liberty Place is a skyscraper complex in Philadelphia, Pennsylvania, United States.  The complex is composed of a 61-story, 945 ft skyscraper called One Liberty Place, a 58-story, 848 ft skyscraper called Two Liberty Place, a two-story shopping mall called the Shops at Liberty Place, and the 14-story Westin Philadelphia Hotel.  Prior to the construction of Liberty Place, there was a "gentlemen's agreement" not to build any structure in Center City higher than the statue of William Penn on top of Philadelphia City Hall.  The tradition lasted until 1984 when developer Willard G. Rouse III of Rouse & Associates announced plans to build an office building complex that included two towers taller than City Hall.  There was a great amount of opposition to the construction of the towers with critics believing breaking the height limit would lead to construction of many more tall skyscrapers, ruining the livability and charm of Center City.  Despite the opposition, construction of One Liberty Place was approved and the first phase of the project began in 1985 and was completed in 1987.  When One Liberty Place was completed, it was the tallest skyscraper in Philadelphia. U.S. Bank Center is a skyscraper located in downtown Milwaukee, Wisconsin, noted for being the tallest building in the state of Wisconsin, and the tallest building between Chicago and Minneapolis.  Standing 601 ft and 42 stories tall, the building has a floor area of 1,077,607 ft2 and it surpassed the Milwaukee City Hall as both the tallest building in the city and the state.  Topped off August 29, 1972, and completed in 1973, it was the headquarters for what eventually became Firstar Corporation from 1973 to 2001.  The building was designed by Bruce Graham and James DeStefano of Skidmore, Owings & Merrill and engineered by Fazlur Rahman Khan.  s of 2017 , the building is home to the headquarters of Foley & Lardner, Robert W. Baird & Company, Sensient Technologies Corporation, and is the Milwaukee office for U.S. Bank, IBM, KPMG, and CBRE. The Pabst Building was a 14-story, 235 ft tall neo-gothic high-rise building in Milwaukee, Wisconsin.  Built in 1891, it was Milwaukee's first skyscraper, and was the tallest building in Milwaukee until the Milwaukee City Hall was finished four years later.  It was demolished in 1981, and the 100 East Wisconsin Building now occupies the site. San Francisco City Hall is the seat of government for the City and County of San Francisco, California.  Re-opened in 1915 in its open space area in the city's Civic Center, it is a Beaux-Arts monument to the City Beautiful movement that epitomized the high-minded American Renaissance of the 1880s to 1917.  The structure's dome is taller than that of the United States Capitol by 42 feet.  The present building replaced an earlier City Hall that was destroyed during the 1906 earthquake, which was two blocks from the present one.  It was bounded by Larkin Street, McAllister Street, and City Hall Avenue (a street, now built over, which ran from the corner of Grove and Larkin to the corner of McAllister and Leavenworth), largely where the current Public Library and U.N. Plaza stand today. Tokyo is the most populated of Japan's 47 prefectures.  In Tokyo, there are 46 buildings and structures that stand taller than 185 metres (607 ft).  The tallest structure in the prefecture is Tokyo Skytree, a lattice tower that rises 634 metres (2,080 ft), which was completed in 2012.  It also stands as the tallest structure in Japan, the tallest tower in the world and the 2nd-tallest freestanding structure in the world.  The tallest building and third-tallest overall structure in Tokyo is the 256-metre-tall (838 ft) Toranomon Hills, which was completed in 2014.  The prefecture's second tallest building is Midtown Tower, which rises 54 stories and 248 metres (814 ft) in height.  Overall, of the 25 tallest buildings and structures in Japan, 16 are in Tokyo. The Milwaukee Center is a 28-story, 426 ft postmodern high-rise building in Milwaukee, Wisconsin.  The building was completed in 1988, during a small building boom in Milwaukee that also included 100 East Wisconsin.  Until 100 East was completed, the Milwaukee Center was the second tallest building in Milwaukee.  The peaked tower, red brick, and the use of green near the top pay homage to the style of the Milwaukee City Hall.  The building is primarily used for offices, but has parking as well. Bridgewater Place, nicknamed The Dalek, is an office and residential skyscraper in Leeds, West Yorkshire, England.  It is the tallest building in Yorkshire, and has held this record since being topped out in September 2005.  It is visible at up to 25 mi from most areas.  Although the tallest building in Yorkshire, it is not the tallest structure.  Emley Moor transmission tower, 13 miles south of Bridgewater Place, is taller and is the tallest structure in the United Kingdom. Philadelphia City Hall, built in 1901 and located at 1 Penn Square, is the seat of government for the city of Philadelphia, Pennsylvania. The Milwaukee City Christmas Tree (1913–1995; 2006–present), also known as Milwaukee City Holiday Tree (1995–2006) is a pine tree that is placed at city hall and decorated by the city council of Milwaukee, Wisconsin, during the Christmas holiday season.  The tradition began in 1913 and continues to this day. The Milwaukee City Hall is in Milwaukee, Wisconsin, United States.  It was finished in 1895, at which time it was the third tallest structure in the United States.  The city hall's bell tower, at 353 feet (108 m), made it the third tallest structure in the nation, behind the Washington Monument and Philadelphia City Hall.  The Hall was Milwaukee's tallest building until completion of the First Wisconsin Center in 1973.
Answer: 1901