William J. Mitchell, the former dean of MIT's School of Architecture and Planning, led the Smart Cities research group at the MIT Media Lab and helped oversee an ambitious expansion of the MIT campus. As architectural advisor to then-President Charles M. Vest, Mitchell guided a $1 billion expansion of the campus that added nearly one million square feet to MIT's 154-acre campus. The building program yielded five innovative architectural projects by world-renowned designers such as Frank Gehry's Stata Center, Kevin Roche's Zesiger Sports and Fitness Center, Steven Holl's Simmons Hall, Charles Correa's Brain and Cognitive Sciences Complex and Fumihiko Maki's Media Lab Complex. In this video, which is excerpted from the MIT150 Infinite History project, Mitchell recalls MIT's architectural "transformative moment."