During and after the Great Depression, the American housing market transformed. While the vast majority of modern mortgages in the U.S. are fully amortizing, this was not true in the early 20th century. Using microdata from a variety of sources, we connect the changes in mortgage type from the 1920s to the 1940s (wherein may more households got access to amortizing loans) to the post-World War II housing boom. Given regulatory and practical limitations on borrowing from remote lenders at this time, the type of mortgage contracts in a given region were intimately tied to the type of lenders nearby. First, we provide new evidence on differences in mortgage design across home, lender, and locale to emphasize the importance of savings and loans locations in reducing barriers to homeownership before the New Deal. Then, we use this characterization of housing lenders to disentangle the individual benefits from access to GI Bill loans from local increases in housing loan availability and provide new evidence on how mortgage contract design shapes the spatial distribution of housing wealth in a period of rapidly rising home prices.