In the spring of 2004, a synergistic team of professors, practitioners, and graduate students coalesced in a graduate planning studio at the University of Pennsylvania (Penn) with the greatest of ambitions: to craft a “Plan for America,” through the year 2050. Their work led to a megaregional revival, weaving the work of Jean Gottman, old regionalists like Benton MacKaye, and New Regionalists like Peter Calthrope into a new perspective on regional planning. In the brief period that followed, a flurry of megaregional research was produced by scholars at Penn, Georgia Tech, the University of Texas at Austin, the Regional Plan Association, and the Lincoln Institute for Land Policy. But nearly a decade into this megaregional revival, old questions about the concept continue to simmer while many new questions emerge, which begs the question: what exactly has this flurry of megaregional research settled? How exactly are megaregions defined and delineated? Do they even have fixed boundaries? Assuming a consensus emerged on how to define and delineate the space, how could such a large and unwieldy scale be governed? Are megaregions functional economic units or merely a product of poorly regulated sprawl development over vast expanses? If they are indeed functional units, how are they interacting or competing with one another for growth, development, and finite public resources? The answers to these questions have been, well, elusive. This thesis begins to remedy this glaring gap in the literature by conducting semi-structured interviews with the key informants credited with leading the conception and evolution of megaregional thought in the U.S. With their aid, this thesis begins to contextualize the provenance, the evolution, the barriers to progress, and the potential future trajectories of the megaregional construct. One of these potential future trajectories – megaregional economic development – is explored between the nation’s only physically linked pair of megaregions: the Texas Triangle and Gulf Coast. In the final chapter of this thesis, recommendations drawn from these analyses are made for the research, the pedagogy, and the practice of planning for megaregions. Together, this triptych of recommendations outlines a path towards a megaregional future. / text