Students of American political development portray the transformation of the bureaucracy from patronage to service as the handiwork of progressive presidents. In this article we explore Congress' programmatic contribution to the transformation of the bureaucracy. Specifically, we examine the development of rural free delivery (RFD) during the 1890's. The early administrative history of RFD and a statistical analysis of initial route allocations identify a strong partisan and electoral rationale for the Republican Congress's decision to dismantle patronage Fourth class post offices and replace them with RFD routes. Freshmen Republican members who faced difficult campaigns in 1900 were the most successful in gathering routes while their Democratic counterparts were the least so. We conclude that the emergence of careerist congressmen looking for opportunities to serve constituents provided an important impetus in the historic reorientation of national policy from patronage to service