During the first half of the twentieth century, there was slow but steady progress toward larger units of public library service, such as county and regional systems. But there was a lag both in the conceptual and the actual development of the central libraries of these systems as strong points for direct service to readers. Librarians were first committed to reach out at the local level and to extend at least minimal service to everyone. The principle of local, direct access to libraries partially prevented attention from being paid to the quality service and subject depth of resources that a centralized system could provide. With the passage of the Library Services Act (LSA) in 1956 and the approval of new standards for public libraries, the ground work was laid to correct this unbalanced development. Most of the earlier efforts to form larger units of service, including those under LSA, were directed toward making books physically convenient for people. Only in the last few years, due to the impetus of some forward-looking state planning and the passage of the library Services and Construction Act in 1964, has effort been focused on building strong central services and resources. (Author/SL)