In planning this symposium, we began with four observations:• Formal nonprofit, nongovernment organizations in the United States and other nations have been shaped by national development over a long period of time, beginning not later than the early 19th century; • relations between church and state have powerfully shaped nonprofit activity; • nonprofit, voluntary, and mutual benefit activities of many kinds have waxed and waned over the years; and • nonprofit activity, as a whole, grew slowly from the beginning of the 19th century to about 1960, but amid considerable controversy, has grown much more rapidly in recent years.These broad outlines of the development of nonprofit and voluntary activity have come into focus only in the past 10 years or so, and we still have much to learn. Fortunately, increasing numbers of scholars, based in several disciplines and many countries, are studying these questions. Knowledge of the development of nonprofit activity over the long term is vital to students of current nonprofit trends, to analysts of nonprofit policy, and to campaigners for increased civic participation. It is valuable to efforts to improve the operations and performance of nonprofit organizations. Knowledge of what has hap- The call for papers for this symposium requested contributions that explored and sought to explain the remarkable expansion of the nonprofit sector in the United States over the past 40 or 50 years. Three of the articles that follow responded to this request. The other three responded to another part of the call for "papers that place the recent United States experience in an international or comparative perspective." These articles define the nonprofit sector as including organizations that are separate from the state, not profit distributing, self-governing, and voluntary (Fisher, 1998;; for a very complete analysis, see Hansmann, 1996). They confirm the view that this sector has deep roots in the histories of several western European nations as well as the United States. These articles demonstrate that the nonprofit sector has expanded quite dramatically, and at nearly the same time on both sides of the Atlantic, since 1960. As a group, these articles also support the view that the size of a nation's nonprofit sector depends very largely on fundamental notions about the nature of the nation and the state, and about citizenship and political obligation-and on the institutional arrangements and policies that put these notions into practice. Especially important, it seems clear, are individual rights, the rights and powers of associations and nonprofit corporations, and relations between state and religion. A nation's commitments in these areas influence the number, activities, and diversity of its associations and nonprofit organizations. The size of a nation's nonprofit sector has also depended, in the four nations considered in these articles, on the size and character of government funding, and on the market for health, education, and welfare services (c.f. .In the United States, Fr...