This study examines ideas that were drawn together by Ebenezer Howard (1850-1928) in his formulation of the Garden City concept originally published in 1898 in his influential book Tomorrow; A Peaceful Path to Real Reform, and subsequently developed at the first Garden City at Letchworth in 1903. Howard readily acknowledged his influences, which included primarily nineteenth century writers on such topics as land nationalization, labour reform, and visionary models for urban settlements. The establishment of Letchworth Garden City was a timely undertaking, one that would leave an enduring legacy, and one that tested many of Howard’s ideas. Developed from the town design by the architects Barry Parker and Raymond Unwin, Letchworth would be the most innovative during the first decade of it’s history, as the various proponents and initial settlers were pioneers in an experiment that demonstrated an integrated approach to town design. The design featured a comprehensive green space system (including an agricultural belt, public green spaces, and private gardens), carefully designed infrastructure, and the zoned organization of functions (town centre, residential neighbourhoods, industrial zone, recreation space, etc.). The company that was formed to establish the new town employed a range of key figures, and a series of organizational structures. An early employee of the company, and ardent advocate for the Garden City movement, was C.B. Purdom (1883-1965), who also published in 1913 a detail account of the first decade of Letchworth’s history. Purdom’s text, entitled The Garden City: A Study in the Development of a Modern Town, is treated in this study as a primary source for interpreting the initial years of the Garden City experiment. The theoretical framework for the study of the legacy of the early Garden City movement is developed from Gilles Deleuze and Félix Guattari’s concept of “assemblage,” together with concepts derived from the contemporary field of landscape ecology, as primarily defined by Richard T.T. Forman (assemblage theory and landscape ecology are considered to be mutually supportive theories). Assemblage theory describes entities as being composed of content, expression, and territorialities that are ideally productive, in that arrangements produce new expressions, organizations, codes, spatialities, and the like. Machine-like in the ways that they function, assemblages also possess agency (the original French term for assemblage is agencement). Landscape ecology provides a system for looking at the structural behaviour of environments (patches, corridors, and matrices) as they are subject to a wide range of flows (energy, organisms, water, nutrients, waste, etc.). Cities and towns manage flow systems through a host of infrastructure and organizational (political, social, economic, bureaucratic, etc.) systems, in highly structured ways, what Deleuze and Guattari describe as “striated” space, which involves a host of boundary mechanisms. These establish highly artificial ecologies that augment, undermine, and bypass the “natural” ecologies that cities participate in. The Garden City, as an artificial ecology, modeled itself on the historic concept of the garden, or the idea, designed by Parker and Unwin, of gardens within a garden (town) within a garden (surrounding agricultural lands). The garden provided a space, a place of creative labour, and could be productive in many ways. The role of gardens (and farms) and gardeners (and farmers) is examined as an operational and ecological model, employed at Letchworth, and subsequently adopted as Garden City ideals proliferated. The legacy of the Garden City movement has been complex, however, many of the original ideas were poorly adapted in subsequent developments of the city during the twentieth century. Innovations included the green space systems (particularly the agricultural belt), the emphasis on townscape, the controlled size of the town, the provision for local enlightened employment, commodious housing for the working classes, the integration of design across scales from the garden to the neighbourhood to the town and region, and the use of modern infrastructure. The relatively low density of the Letchworth fabric (See Unwin’s essay “Nothing Gained by Overcrowding!”) has been both the strength of the Garden City model, and also, paradoxically, its greatest weakness. More recently the ecological potential inherent to the design has been stressed. As an assemblage the Garden City has produced many concepts and influenced many movements in urban design. With respect to agency, the writings of Howard would have a dramatic impact on urbanization across the twentieth century influencing settlement models, concepts of greenspace, and the proliferation of suburban environments. The bureaucratic systems that were put in place in order to realize Letchworth relied on the machinations of private enterprise, and were not as innovative as Howard imagined; the same can be said of his efforts to create a new system for land ownership. The most vital agents were the high profile figures like Howard, Unwin, and members of the original company, along with the more anonymous early settlers in Letchworth who established businesses, institutions, and social/cultural organizations. The most important urban agent in the Garden City model was the gardener who was intended to produce food and ecologies, and to learn how to function as a collective figure; the history of gardening demonstrates that there are general attributes associated with gardening as the creation of productive artificial ecologies. With respect to territoriality, or the structural organization of land, Letchworth was arranged according to a plan that carefully zoned areas of the estate by function, and adjacency. This creates a patchwork of uses, or an ecology, that by its arrangement precludes the organization of flows. This is also supported by the system of divisions, or boundaries, within the design of the community; the regulated zoning of land within cities remains a controversial topic in contemporary cities. The highly managed control of flows in urban environments is evident at Letchworth in the prescribed nature of the infrastructure and the regulation and control of the design. The major mitigating element in the plan is the role of greenspace (agricultural belt, gardens, parks, tree canopies, etc.), which combined to act as an ecology that attempted to harmonize with surrounding farmland. As Deleuze and Guattari note, cities manage flows, and the better control of flows in urban environments will lead to better functioning urban ecologies. The model put forward by the Garden City movement at the beginning of the twentieth century has left an enduring legacy, both positive and negative. Many of the principles employed by the early pioneers are now considered to be integral to the contemporary sustainable city. One of the most widely adopted ideas has been the greenbelt (and its many derivations), which has been employed to control the growth of cities and to preserve agricultural land and natural areas adjacent to cities; these have both positive and negative effects. As the Garden City movement stressed, cities cannot be separated from their regions (hinterland), they are a fusion between city and country, local and global. The highly codified structure of early Letchworth evident in the organization of land and infrastructure remains as a weakness, but its emphasis on the garden remains its strength. Cities as assemblages and ecologies must remain productive (socially, politically spatially, etc.) in order to remain vital, contemporary cities must continue to reinvent themselves to achieve sustainability.