The first developed garden city, Letchworth, was designed by Raymond Unwin and Barry Parker, who were pivotal figures in the garden city movement. This movement was inspired by the idea of creating self-sufficient communities surrounded by greenbelts, combining the benefits of both urban and rural environments.
Unwin and Parker approached the design of Letchworth with the philosophy of integrating green spaces, residential areas, and community amenities, ensuring that the development would promote social well-being and a healthy living environment. Their thoughtful planning included wide streets, parks, and communal areas, showcasing the principles that would later influence urban planning globally.
The other individuals listed, such as Daniel Burnham, Oscar Niemeyer, Louis de Soisson, and Lucio Costa, were influential architects and planners in their own rights, contributing to various notable projects, but they were not involved with the design of Letchworth. Their work focused on different architectural styles or urban planning projects that did not center around the garden city concept. Thus, the choice highlighting Unwin and Parker accurately connects directly to the origins of the garden city movement exemplified by Letchworth.