Chicago tumultuous 1968 Democratic National Convention, which featured physical confrontations both inside and outside the convention hall, with anti-war protesters, journalists and bystanders being beaten by police. Major construction projects, including the Sears Tower (now known as the Willis Tower, which in 1974 became the world's tallest building), University of Illinois at Chicago, McCormick Place, and O'Hare International Airport, were undertaken during Richard J. Daley's tenure. In 1979, Jane Byrne, the city's first female mayor, was elected. She was notable for temporarily moving into the crime-ridden Cabrini-Green housing project and for leading Chicago's school system out of a financial crisis. In
Willis Tower unfinished World Trade Center to become the world's tallest building. The height was restricted by a limit imposed by the Federal Aviation Administration (FAA) to protect air traffic. The financing of the tower was provided by the Sears company. It was topped with two antennas to permit local television and radio broadcasts. Sears and the City of Chicago approved the design, and the first steel was put in place in April 1971. The structure was completed in May 1973. The construction cost about US$150 million at the time, equivalent to $ million in 2019. By comparison, Taipei 101, built in