Chicago is the home of the skyscraper, and the influence of the Chicago School of architecture has been felt around the world. Today we look at five firms responsible for building the city's past, present and future.

1. Holabird & Root

This Chicago mainstay was at the forefront of the First School of Chicago architecture with early skyscrapers like the Marquette Building (where the firm offices), the Tacoma Building and the third Palmer House hotel (pictured). The firm was founded in 1880 by William Holabird and Ossian Cole Simonds as Holabird & Simonds. Martin Roche joined a year later. William Holabird's son John Augur Holabird and John Wellborn Root renamed it Holabird & Root after the deaths of William Holabird and Martin Roche, and adopted an art deco style. In 2013, the firm's design for University of Chicago's Logan Center for Creative and Performing Arts won a Chicago Building Congress merit award for new construction.

2. Graham, Anderson, Probst & White

Ernest R. Graham, a partner of Daniel Burnham, founded this firm with Burnham's sons Daniel Jr. and Hubert in 1912. After the Burnhams left to form their own practice in 1917, Graham promoted William Peirce Anderson, Edward Mathias Probst and Howard Judson White as partners. The firm adopted a Beaux-Arts style and was known for using sculpture in its building designs. The firm's notable buildings include the Wrigley Building, Merchandise Mart, Shedd Aquarium, Field Museum (shown), Civic Opera House and the Old Main Post Office. GAP&W remained in operation until 2006.

3. Bertrand Goldberg

The Chicago-born, Bauhaus-trained Goldberg got his start working in the offices of Mies van der Rohe. He returned to Chicago and opened his own office in 1937. Goldberg was best known for his unconventional designs using standard materials such as concrete and plywood, most notably in the twin corncob-shaped towers at Marina City, which was the tallest concrete residential building in the world when it opened. Goldberg also designed the now-demolished Historic Prentice Women's Hospital, River City (pictured) and Hilliard Homes.

4. Skidmore, Owings & Merrill

Louis Skidmore and Nathaniel Owings formed this firm in 1936. They were joined three years later by John O. Merrill and went on to specialize in "glass-box" skyscrapers like the Brunswick Building, John Hancock Center, the Inland Steel Building, NBC Tower and Willis Tower (pictured). Today, SOM is one of the world's largest architecture firms. Its most recent Chicago projects include the Chicago Public Library's Chinatown branch, Trump Tower and the master plan for Millennium Park.

5. Studio Gang Architects

MacArthur fellow Jeanne Gang founded this firm in 1997, specializing in sustainability, collaboration and material experimentation. Gang's Aqua Tower (shown) was her first skyscraper project and the largest skyscraper project awarded to a firm headed by a woman at the time. It eventually won the Emporis 2009 skyscraper of the year. Gang's other works range from the under construction City Hyde Park, Columbia College Chicago's media production center, Lincoln Park Zoo's nature boardwalk, and Wanda Vista tower, whose design plan was recently approved by the Plan Commission. Wanda Tower will be Chicago's third-tallest building when completed.