The already vibrant charitable sector in the US is in the midst of a transformation that is altering both the manner in which donations occur and the causes that are supported. Philanthropy in Transition examines the unique role that charitable giving has played in the US, from colonial times to the present. The rising importance of new means of contributing, particularly giving through buying or investing, is considered. These new models of philanthropy have expanded the ways by which ethical consumers or investors can support a cause. Although these innovations represent a revolution in the structure of philanthropy, they introduce significant complexity to the act of giving – donors are far removed from recipients – and this may weaken the impact of contributing. This transformation is also likely to accelerate the rising importance of web-based promotion and fund-raising, as traditional nonprofits compete with social market enterprises and social impact investmentsfor funds.