1. Frederick Law Olmstead
Louis Sullivan
Frederick Law Olmstead
Frank Lloyd-Wright
Le Corbusier

2. Frederick Law Olmstead New York Central Park, 1858
The design of Central Park embodies Olmsted's social consciousness and commitment to egalitarian ideals. Influenced by Downing and his own observations regarding social class in England, China and the American South, Olmsted believed that the common green space must always be equally accessible to all citizens. This principle is now fundamental to the idea of a "public park", but was not assumed as necessary then. Olmsted's tenure as park commissioner in New York was a long struggle to preserve that idea.[
Frederick Law Olmstead New York Central Park, 1858

3. Frederick Law Olmstead The Mall New York Central Park, 1858
The design of Central Park embodies Olmsted's social consciousness and commitment to egalitarian ideals. Influenced by Downing and his own observations regarding social class in England, China and the American South, Olmsted believed that the common green space must always be equally accessible to all citizens. This principle is now fundamental to the idea of a "public park", but was not assumed as necessary then. Olmsted's tenure as park commissioner in New York was a long struggle to preserve that idea.[
Frederick Law Olmstead The Mall New York Central Park, 1858

4. Frederick Law Olmstead Bethesda Terrace New York Central Park, 1858
The design of Central Park embodies Olmsted's social consciousness and commitment to egalitarian ideals. Influenced by Downing and his own observations regarding social class in England, China and the American South, Olmsted believed that the common green space must always be equally accessible to all citizens. This principle is now fundamental to the idea of a "public park", but was not assumed as necessary then. Olmsted's tenure as park commissioner in New York was a long struggle to preserve that idea.[

5. Frederick Law Olmstead The Great Lawn New York Central Park, 1858
The design of Central Park embodies Olmsted's social consciousness and commitment to egalitarian ideals. Influenced by Downing and his own observations regarding social class in England, China and the American South, Olmsted believed that the common green space must always be equally accessible to all citizens. This principle is now fundamental to the idea of a "public park", but was not assumed as necessary then. Olmsted's tenure as park commissioner in New York was a long struggle to preserve that idea.[
Frederick Law Olmstead The Great Lawn New York Central Park, 1858

7. Louis Sullivan Guaranty Building 1895Buffalo, NY
All of these elements can be found in Sullivan's widely-admired Guaranty Building, which he designed while partnered with Adler. Completed in 1895, this office building in Buffalo, New York is in the Palazzo style, visibly divided into three "zones" of design: a plain, wide-windowed base for the ground-level shops; the main office block, with vertical ribbons of masonry rising unimpeded across nine upper floors to emphasize the building's height; and an ornamented cornice perforated by round windows at the roof level, where the building's mechanical units (like the elevator motors) were housed. The cornice crawls with Sullivan's trademark Art Nouveau vines; each ground-floor entrance is topped by a semi-circular arch.

8. Louis Sullivan Prudential Building Buffalo, NY
Prior to the late 19th century, the weight of a multistory building had to be supported principally by the strength of its walls. The taller the building, the more strain this placed on the lower sections of the building; since there were clear engineering limits to the weight such "load-bearing" walls could sustain, large designs meant massively thick walls on the ground floors, and definite limits on the building's height.
The development of cheap, versatile steel in the second half of the 19th century changed those rules. America was in the midst of rapid social and economic growth that made for great opportunities in architectural design. A much more urbanized society was forming and the society called out for new, larger buildings. The mass production of steel was the main driving force behind the ability to build skyscrapers during the mid 1880s.
The people in Midwestern America felt less social pressure to conform to the ways and styles of the architectural past. By assembling a framework of steel girders, architects and builders could suddenly create tall, slender buildings with a strong and relatively delicate steel skeleton. The rest of the building's elements—the walls, floors, ceilings, and windows—were suspended from the steel, which carried the weight. This new way of constructing buildings, so-called "column-frame" construction, pushed them up rather than out. The steel weight-bearing frame allowed not just taller buildings, but permitted much larger windows, which meant more daylight reaching interior spaces. Interior walls became thinner, which created more usable floor space.
The technical limits of weight-bearing masonry had always imposed formal as well as structural constraints; those constraints were suddenly gone. None of the historical precedents were any help, and this new freedom created a kind of technical and stylistic crisis.
Sullivan was the first to cope with that crisis. He addressed it by embracing the changes that came with the steel frame, creating a grammar of form for the high rise (base, shaft, and pediment), simplifying the appearance of the building by breaking away from historical styles, using his own intricate flora designs, in vertical bands, to draw the eye upwards and emphasize the building's vertical form, and relating the shape of the building to its specific purpose. All this was revolutionary, appealingly honest, and commercially successful.
Louis Sullivan coined the phrase "form ever follows function", which, shortened to "form follows function," would become the great battle-cry of modernist architects. This credo, which placed the demands of practical use above aesthetics, would later be taken by influential designers to imply that decorative elements, which architects call "ornament," were superfluous in modern buildings. But Sullivan himself neither thought nor designed along such dogmatic lines during the peak of his career. Indeed, while his buildings could be spare and crisp in their principal masses, he often punctuated their plain surfaces with eruptions of lush Art Nouveau and something like Celtic Revival decorations, usually cast in iron or terra cotta, and ranging from organic forms like vines and ivy, to more geometric designs, and interlace, inspired by his Irish design heritage. Terra cotta is lighter and easier to work with than stone masonry. Sullivan used it in his architecture because it had a malleability that was appropriate for his ornament. Probably the most famous example is the writhing green ironwork that covers the entrance canopies of the Carson Pirie Scott store on South State Street. These ornaments, often executed by the talented younger draftsman in Sullivan's employ, would eventually become Sullivan's trademark; to students of architecture, they are his instantly-recognizable signature.
Another signature element of Sullivan's work is the massive, semi-circular arch. Sullivan employed such arches throughout his career—in shaping entrances, in framing windows, or as interior design.
All of these elements can be found in Sullivan's widely-admired Guaranty Building, which he designed while partnered with Adler. Completed in 1895, this office building in Buffalo, New York is in the Palazzo style, visibly divided into three "zones" of design: a plain, wide-windowed base for the ground-level shops; the main office block, with vertical ribbons of masonry rising unimpeded across nine upper floors to emphasize the building's height; and an ornamented cornice perforated by round windows at the roof level, where the building's mechanical units (like the elevator motors) were housed. The cornice crawls with Sullivan's trademark Art Nouveau vines; each ground-floor entrance is topped by a semi-circular arch.

12. Frank Lloyd Wright Frederick C. Robie House 1908-1910 Chicago, Illinois

13. Frank Lloyd Wright Frederick C. Robie House 1908-1910 Chicago, Illinois

14. Frank Lloyd Wright Frederick C. Robie House 1908-1910 Chicago, Illinois

15. Le Corbusier Villa Savoye 1928-31 Poissy, France

16. Le Corbusier Villa Savoye 1928-31 Poissy, France

17. Le Corbusier Heidi Weber Pavilion 1965 Zurich, Switzerland
Centre Le Corbusier / Heidi Weber Pavilion Hoeschgasse 8  Zurich
Le Corbusier 1965
Also known as the Centre Le Corbusier, the Heidi Weber Pavilion was completed after Corbusier's death and is now a (rarely open) museum and gallery.

18. Le Corbusier Heidi Weber Pavilion 1965 Zurich, Switzerland
Centre Le Corbusier / Heidi Weber Pavilion Hoeschgasse 8  Zurich
Le Corbusier 1965
Also known as the Centre Le Corbusier, the Heidi Weber Pavilion was completed after Corbusier's death and is now a (rarely open) museum and gallery.
Le Corbusier Heidi Weber Pavilion Zurich, Switzerland

19. Le Corbusier Notre Dame du Haut 1950-54 Ronchamp

20. Le Corbusier Notre Dame du Haut 1950-54 Ronchamp

21. Le Corbusier Notre Dame du Haut 1950-54 Ronchamp

22. Bjarke Ingels' architecture
Bjarke Ingels is principal of BIG, based in Copenhagen. An alumnus of Rem Koolhaas' OMA practice, Ingels takes a similar approach: experimenting with pure space, but never losing sight of the building as a solution to a real-world problem. His manifesto "Yes Is More" takes the form of a giant cartoon strip, 130 meters long, that reminds people to keep thinking big -- to see all our modern problems as challenges that inspire us.
His deeply-thought-out and often rather large works -- including several skyscrapers and mixed-use projects in a developing section of Copenhagen, plus a project for a new commercial harbor-island --work to bring coherence to the urban fabric and to help their occupants and users lead better lives. His most famous works include: the Stavanger Concert House, Tallinn’s city hall and the VM Houses. He recently won a competition to design Copenhagen’s waste-to-energy plant with a design that will place a ski slope on top of the structure.