The idea, and to a lesser extent the reality, of themodern home improvement store was born in the first quarter of the twentieth century. After 1905 the manufacturers of mail-order kit houses soon grew to threaten the local monopoly of retail building suppliers. Themost important of these suppliers were the lumber merchants who provided most of the materials and credit used by building contractors. At first dealers responded by mounting boycotts and by supporting trade-at-home campaigns, but these were successfully challenged in court. A survey of trade journals shows that after 1914 dealers began to act more constructively. Encouraged by the trade press, and helped by state and national associations, by the 1920s they were advertising more effectively and offering a widening range of goods and services to consumers, including house plans. Because many new customers were women, dealers had to hire more courteous staff, clean up their yards, mount better displays, build showrooms and, in time, relocate to more salubrious and heavily-trafficked parts of town. The emergence of the home improvement store is a significant chapter in the history of urban housing, and especially the marketing of housing services, in the twentieth century.