On the eve of Teach For America's tenth reunion, Wendy Kopp, the 32-year-old founder and leader of the national teacher corps, is considering how to increase the impact of the organization. To date, the organization has placed 5,000 teachers in under-resourced public schools. Kopp wonders how to expand the corps-both in size and scope-without compromising the quality of the teachers and the entrepreneurial culture of the organization. Critical to this endeavor will be understanding how to leverage her resource appropriately. She has just hired a COO and a director of site expansion to help with this effort.

The San Francisco Opera, second largest in the United States, has embarked on a initiative to attract a larger audience and more support from Silicon Valley. Given that the opera's traditional constituency is the older, wealthier residents of San Francisco, this represents an important change. The opera also hopes to use Silicon Valley relationships to strengthen its Web site.

The National Campaign to Prevent Teen Pregnancy was founded in 1995 to bring together a variety of efforts to reduce teen pregnancy in the United States. Over the last four years the campaign has recruited a prestigious board, developed effective programs for influencing the media, attracted a strong staff, sponsored research on the causes of the high teen pregnancy rate in the United States, and raised significant funds. The campaign's board and staff must now decide how rapidly to grow, whether to establish a local presence, what their research priorities should be, and how to work effectively with others in the field.

Can an organization with a four-decade track record of growth avoid becoming the victim of its own success? Since the Nature Conservancy was founded in 1951, it has worked to save threatened habitats and species by buying and setting aside land. Year by year, the number of acres under its protection has increased, membership has risen, and donations have grown. The leader of any nonprofit company might justifiably envy the Conservancy's performance, but its president and CEO, John Sawhill, isn't satisfied. Since taking the job in 1990, Sawhill has led a major shift in strategy with far-reaching implications for the day-to-day activities of the organization's 2,000 employees. He believes that the Conservancy must change now to achieve its mission over the long term. In this interview, he discusses the challenges inherent in refocusing a large, successful, mission-driven organization.