Monadnock Building

1:1500 scale miniature paper model, about 3.5 inches long when built

The north half of this early skyscraper was designed by Daniel Burnham and John Root. When completed in 1891 it was the world's tallest office tower at 17 stories. Six-foot thick walls at the base represent the height limits of all-masonry construction. The south addition by William Holabird and Martin Roche, built just two years later, utilized new techniques of steel frame construction.

Read more:

• Official website of the Monadnock Building
• Geoffrey Baer explains why the walls of the building are so thick
• Council on Tall Buildings and Urban Habitat article explains the mix of masonry and steel frame construction used in the north end of the building
• WBEZ examines the difficulty supporting the heavy building on Chicago's viscous clay soil
• The dense block of offices required four dedicated letter carriers in 1900
• The building is named after Mount Monadnock in New Hampshire, from a Native American word describing an isolated peak
• Chicago 1890: The Skyscraper and the Modern City, by Joanna Merwood-Salisbury, published by University Of Chicago Press (2009)