Skyscrapers Architects John Wellborn Root

The Flatiron Building, or Fuller Building as it was originally called, is located at 175 Fifth Avenue in the borough of Manhattan, and is considered to be one of the first skyscrapers ever built. Upon completion in 1902 it was one of the tallest buildings in New York City. The building sits on a triangular island block at 23rd Street, Fifth Avenue, and Broadway, anchoring the south (downtown) end of Madison Square.

The Monadnock Building, also known as Monadnock Block, is a historic proto-skyscraper in the Loop district of downtown Chicago, Illinois. It is arguably the world's first skyscraper. The Monadnock is the tallest commercial building in the world with masonry load-bearing walls. It is located at 53 West Jackson Blvd. The seventeen-story building stands 197 feet (60 meters) tall.

The Montauk Building - also often referred to as Montauk Block - was a high-rise building in Chicago, Illinois. Designed by John Wellborn Root Sr. and Daniel Burnham, it was built in 1882–1883, and was demolished in 1902. According to Thomas Talmadge, "What Chartres was to the Gothic cathedral, the Montauk Block was to the high commercial building".

The Reliance Building is the first skyscraper to have large plate glass windows make up the majority of its surface area, foreshadowing a feature of skyscrapers that would become dominant in the 20th century. It is located at 32 North State Street, Chicago, Illinois, and as of 2006 houses the Hotel Burnham. The Reliance building was listed on the National Register of Historic Places in 1970; and on January 7, 1976, it was designated a National Historic Landmark.

The Society for Savings Building, also known as the Society Corp. Building, is a high-rise building on Public Square in downtown Cleveland, Ohio, United States. The building was constructed in 1889, and stood as the tallest building in Cleveland until 1896, when it was surpassed by the 221-foot (67 m) Guardian Bank Building. The building stands 152 feet (46 m) tall, with 10 floors.