Legacy cities – also known as shrinking, rust belt, and post-industrial cities – are places facing persistent population decline, disinvestment, and structural economic challenges. Scholars and practitioners argue that historic buildings are among the key assets for neighborhood stabilization and revitalization, yet demolition of existing buildings is a dominant public policy approach in legacy cities. Using a mix of quantitative and qualitative methods, this three-essay dissertation (1) develops a typology of legacy city neighborhoods across five cities (Baltimore, Cleveland, Philadelphia, Richmond, & St. Louis) and five census decades (1970-2010), (2) identifies patterns of federal historic rehabilitation tax credit (RTC) activity and evaluates the effects of RTC investments on racial, socioeconomic, and housing characteristics across legacy city neighborhood types from 2000 to 2010, and (3) examines how and why RTCs are deployed as a preservation tool in different neighborhood contexts. Hierarchical cluster analysis and discriminant analysis are employed in the first essay, identifying eight distinct neighborhood types (Established & Stable Homeowners; Highly Bifurcated; Competitive, Educated, & Struggling; Educated Newcomers; White Immigrants; Declining & Black; Black, Stressed, & Disadvantaged; Collapsed Urban Core) and supporting the coherency of legacy cities as a meaningful analytic grouping. In the second essay, descriptive statistics show the distribution of RTC activity across all legacy city neighborhood types, and a difference-in-differences regression model counters arguments in the existing literature that RTCs contribute to revitalization or gentrification in legacy cities. Using key person interviews and a comparative case study approach of two St. Louis neighborhoods, the final essay uncovers key lessons as to how and why the RTC functions as a preservation and reinvestment tool across different types of neighborhoods in a declining citywide context, including the size/scale of historic urban fabric, importance of stable neighborhoods as testing grounds for RTC investments, role of situational conditions and cultural contexts, and the economic and cultural values rooted in RTC decision-making.