1. Gensler is a global architecture and design firm with over 5,000 employees in more than 50 locations worldwide. The firm has designed some of the most iconic buildings in the world, including the Shanghai Tower, the new San Francisco International Airport, and the Mercedes-Benz Stadium in Atlanta.
2. Skidmore, Owings & Merrill (SOM) is another global architecture and engineering firm with over 10,000 employees in more than 30 locations worldwide. SOM has designed some of the tallest buildings in the world, including the Burj Khalifa in Dubai, the One World Trade Center in New York City, and the Willis Tower in Chicago.
3. HOK is a global architecture, engineering, and design firm with over 2,300 employees in more than 25 locations worldwide. HOK has designed some of the most sustainable buildings in the world, including the LEED Platinum-certified Bank of America Tower in New York City and the LEED Gold-certified Seattle Public Library.
4. NBBJ is a global architecture, interior design, and planning firm with over 2,000 employees in more than 15 locations worldwide. NBBJ has designed some of the most innovative and cutting-edge buildings in the world, including the Amazon Spheres in Seattle and the Googleplex in Mountain View, California.
5. Morphosis is an architecture and design firm based in Santa Monica, California. Morphosis is known for its experimental and avant-garde designs, and has won numerous awards for its work, including the Pritzker Architecture Prize in 2006.
These are just a few of the many great architectural firms in the United States. Each of these firms has a unique style and approach to design, and has created some of the most iconic buildings in the world.