Many explanations of competitive advantage view place as a secondary factor. Organizational studies models tend to be considered aspatially, yet most are inherently geographic. It is important to consider the impact that geography has on the success or failure of an individual firm or a sector. This dissertation examines how location impacts the US farm machinery industry through an empirical analysis of Porter’s Theory of Competitive Advantage. Contributing to this empirical test are other bodies of literature including models for headquarters and research and development siting, product life cycle theory, industry life cycle theory, and green technologies as a driver of competitive advantage. The US farm machinery industry is composed of three firms: Deere and Company, Case New Holland, and the Allis-Gleaner Corporation. Theory-elaborating case study methodology, informed by archival data, publically available documents, trade show reconnaissance, and plant tours, coupled with map and content analysis allows for a deeper understanding of how geography impacts competitive advantage in the sector. Comparing findings from these geographic case studies to Porter’s results led to a new understanding of competitive advantage for mature manufacturing in a globalized economy. Previous analysis found Porter’s single diamond, which focuses on local conditions for competitive advantage, most appropriate for explaining mature industries in advanced market economies. This study found, however, that as mature industries increasingly pursue a global focus, a double diamond model, which takes into account both local and global conditions for competitive advantage, is more appropriate, even in an advanced economy. This research also found that, much like second-tier cities are desirable for headquarters and research and development siting, second-tier countries (that can provide high-skill labor at lower prices) are increasingly attractive for manufacturing operations. The need for modifications to product life cycle theory that take into account the impact of these countries as well as the effects of nationalism on manufacturing decisions in mature economies were also uncovered by this dissertation. This research demonstrates the continued importance of place to understanding competitive advantage, not only in the US farm machinery industry, but generally for mature manufacturing as a whole.