Original situation or character of site: After completion the towers were marketed as a cooperative apartment building and are fully occupied by September 1952.
The twin structures located perpendicular from each other are considered among Chicago’s most famous and prestigious apartment buildings. The pair of twenty-six-story towers at 860/ 880 Lake Shore Drive are located along the City's Gold Coast Extending from Chestnut Street north one block to Delaware Street with a view to Lake Michigan across the drive. Also important, is the site plan of the two buildings, which is shaped in a triangular shape and working with the position of 860 and 880 allows both buildings maximum views of the Lake Michigan.
Name(s) of surrounding area/building(s): The Promontory Apartments,5530 S Shore Drive, Chicago, IL
Other relations: The Promontory Apartments (5530 S Shore Drive, Chicago) constructed by Mies van der Rohe in 1948 for Herbert Greenwald were originally designed to have a glass and steel exterior. The final design instead utilized concrete with exposed columns, however the buildings alternate drawings were later developed into the design of 860-880 Lake Shore Drive. As stated above, in January 2007, an approximately $7.5 million restoration of the buildings was announced that will include travertine repair, restoration of the plaza and lobby interiors, exterior steel returned to the original black color, restoration of exterior glass panes to sandblasted glass.
The technical significance of 860-880 Lake Shore Drive is seen in both Mies’ choice of materials and structural approach. The buildings are considered his first application of glass and steel curtain wall on high-rise apartments houses in Chicago. The materials themselves are also one of the few steel and glass residential high rises in Chicago.
“The Glass Houses.” Known as a modern architecture landmark, the buildings also represent a sleek style of modern living in its contemporary structure. The building is on the United States National Register and also was the first Mie’s van der Rohe designated landmark in the city of Chicago.
The cultural and aesthetic evaluation can be seen through the buildings comparative significance. The towers are considered trailblazers in international style and the evolution of both the curtain wall and Mies van der Rohe's design influence on the city of Chicago. Recently featured on a USPS postal stamp celebrating “Master works of Modern Architecture”, the buildings are considered the symbol of the international style in Chicago. Further serving as inspiration for similar structures around the world, 860- 880 Lake Shore Drive is still considered one of the most pure examples of international style in a skyscraper. Canonical status : As a symbol of modern architecture, the buildings have held a status of being designed by a “celebrity architect.” As the appreciation of modernism has increased in recent years the role of these modern towers are integral in understanding the evolution of modern design in residential structures as well as the architectural and design growth of Mies van der Rohe. Furthermore, the buildings reflect and enforce the status of Chicago as being on the forefront of architectural patronage and design during the 20th century.
The referential value of the buildings is their place as one of the first modern residential high rise structures in Chicago. The structures capture a moment in modern history that combines both a social and aesthetic crossroads in the city of Chicago. Capturing the sentiment of “modern living” reflected in the composition of glass and steel, the towers reflect both the sentiment of the mid twentieth century and the role of architecture in reflecting the aspirations of its generation of architects. Its status as a symbol of the International Style in Chicago and around the world only serves to reinforce the importance of most pure examples of the international style in a skyscraper. 860 and 880 Lake Shore Drive also mark a point of when the Chicago School of Architecture (started by Sullivan, Burnham and Root et al.) reaches its “height of modernism” (in the use of architectural innovations)- with the glass and steel construction, high rise structure and curtain wall façade. All advances put in place with the work of the original architects of the Chicago school and achieving full recognition and application by Mies and other architects at this point.
Avery Archives, Columbia University, New York, NY
Selected Bibliography-“860-880 Lake Shore Drive.” Chicago Landmarks. http://www.ci.chi.il.us 
Landmarks/numbers/860880LSD.html. Accessed 4 February 2007.
Abrams, Janet. “Modernity…860-880 Lake Shore Drive in Chicago.” Metropolis.
Bey Talks to Lifson, Lifson Talks up rehab of Mies 860-880.” Architecture Chicago October 1992, v.12, no.3. pp.76-77
Plus. 11 January 2007. http://arcchicago.blogspot.com/ . Accessed 4 February 2007.
Carter, Peter. Mies van der Rohe at Work. New Ed edition, 1999. Phaidon Press, New Kamin, Blair. “2 of Mies’ Best Still in a Glass By themselves.” Chicago Tribune. York. P.52
Lifson, Edward. “860 - 880 N. Lake Shore Drive by Mies to be Restored!” The New Chicago, Il. 20 September 1992, Final Edition. Modernist. 9 January 2007. http://edwardlifson.blogspot.com/2007/01/860-880.html  Accessed 4 February 2007.
Pomaranc, Joan. 860-880 Lake Shore Drive. Commission on Chicago Historical
Sell, Shawn. “The Only Game in Town: Under Chicago’s New Landmarks Law, Politics Architectural Landmarks. Chicago, Il, 1980. Rule Preservation.” Historic Preservation. May-June 1996, v.48, no.3. p.24