Throughout the twentieth century various urban design theories came into light. These theories were sometimes original and sometimes derivative of some previous theory.These theories can be broadly categorized in different urban design models. The chronological study of different urban design theories gives us the theoretical and generic evolution of urban design. The practical evolution of urban design in any city can be different from the generic evolution of urban design. This thesis examines the urban design of three Midwestern American cities from their origins to the present day. The urban design of these cities, related to different time periods is then compared with the different urban design models to understand the "Evolution of Urban Design in Practice".