The document provides an overview of the nonprofit sector in the United States, including its history and growth out of pioneers addressing gaps in services over the past few hundred years. It discusses the main types of nonprofit groupings such as charities, foundations, social welfare organizations, and professional/trade associations. It also outlines why nonprofits are tax exempt and what it takes to become a nonprofit, including establishing a vision/mission, staff/volunteer/donor base, board, and day-to-day management expectations.