Making the Imagined Real seeks to explain variation in the development of new urban elevated linear parks between 1999 and 2012 using case studies in New York (High Line), Chicago (Bloomingdale Trail) and Philadelphia (Reading Viaduct). In those three locations, nonprofit community groups have attempted to or have successfully created public-private coalitions to re-purpose abandoned public spaces into elevated urban linear parks. The cities are similar, the projects started around the same time, the groups are trying to do similar things, and yet the three projects are in very different stages of project development. Looking at these three cases together, though they are in varying stages of completion, can shed light on the process of entrepreneurship. The role of economic interest in urban development has been well-studied and documented, but an economics-based viewpoint alone does not explain why individuals without a clear economic interest devote time and effort to making these parks a reality. I argue that success in these ventures also depends upon these community groups using imagery, symbolism, and discourse strategically to drive institutional change.