One Prudential Plaza (or the Prudential Building) is a 41-story structure in Chicago. It was finished in 1955 as the headquarters for Prudential's Mid-America company. The building is known for its 311 feet antenna. The building is 601 feet (183 m) without the antenna. With the antenna, the building is 912 feet (270 m) high. The building and its "sister" building, the Two Prudential Plaza, was sold in May 2006 for $470 million dollars. It was the 2012 Obama campaign headquarters for the United States presidential election, 2012.