08/04/2010 06:49 pm ET | Updated May 25, 2011

The Giving Pledge: Which Wealthy Families Are Joining Buffett And Gates? (PHOTOS)

Billionaires Warren Buffett and Bill and Melinda Gates have pledged to give the majority of their fortunes to charity -- and have asked other wealthy American families to do the same. Today, they announced that 40 families have accepted the challenge. In order to meet the terms set out by Buffett and the Gates family, participants had to agree to give at least half of their wealth away to charitable causes.

The information below was collected from, a website set up to provide a full list of the individuals and families who are a part of 'The Giving Pledge.'

The Giving Pledge: America's Wealthy Families Give Majority Away