CHICAGO—The John D. and Catherine T. MacArthur Foundation went on a wild endowment binge last weekend, recklessly giving away more than $170 million in grants and fellowships in a 48-hour span.

Fanton and Hutton in the midst of their wild endowing spree.

"We got pretty out of control there with the endowing," said foundation president Jonathon Fanton, icing down his check-writing hand while recovering Monday. "It started Friday afternoon, when [Vice President and Chief Financial Officer] Lyn [Hutton] suggested we give a grant to the Foundation for Urban Renewal for their tireless efforts to rebuild America's struggling inner cities. Then, [Treasurer] Marc [Yanchura] said Save Our Cities was doing even better work, so we threw them on the pile, too. Things kind of snowballed from there, and by 4 a.m., we'd given $81 million in grants to 16 different groups. I think we even gave a few million to [rival philanthropic organization] Pew Charitable Trusts."

After a brief pause Saturday afternoon, the endowing resumed. The generous support of nonprofit activities in the arts and culture, education, the environment, health and human services, and public policy continued deep into the night.

"Saturday, around 3 p.m., we all went out for breakfast. Over eggs and Bloody Marys, we talked about the night before and how crazy we'd gotten," Fanton said. "But when the sun went down that night, we started right back up again with the endowing. Mostly to public radio networks under the General Program, but also 20 or 30 theater companies and a shitload of PBS fellowships. Half the people who've ever appeared on Sesame Street are MacArthur Fellows now."

While the bulk of the money went to groups falling under the foundation's Program on Human and Community Development, a considerable portion went to less noble causes, including the 3-2-1 Contact Preservation Society and the Recumbent Bicycling Hall Of Fame.

"At the time, it felt like the right thing to do," Fanton said of the binge. "It wasn't until we woke up Sunday morning that we were like, 'Holy shit... how much did we endow this weekend?'"

According to Vice-Chairman Elizabeth McCormack, the endowment binge is a result of the foundation's low self-esteem.

"It seems like the only time we feel good is when we're awarding endowments," McCormack said. "The pain and pressures of the outside world vanish, and it's as though you and the beneficiary are all that exist. That's a tough high to come down from. Deep down, we knew it was reckless, but we kept making rationalizations like, 'Well, the Program on Global Security and Sustainability is of heightened importance during this crossroads moment in world history.'"

McCormack's concern was echoed by experts in the field of grant-writing.

"When the stress of operating a charitable foundation gets to be too much, the urge to endow often takes control, overriding all logic and common sense," said Martin Wingreen, author of Giving Their All: The Secret Shame Of Compulsive Philanthropy. "Under the sway of such an intense sensation, the grant giver just can't resist funding every non-profit in sight."

Acknowledging that his group "has a problem," Fanton pledged that the foundation's Board of Directors would seek endowment counseling and join a philanthropy-addiction support group.

"After hearing about our endowment binge, the chair of the Andrew W. Mellon Foundation gave me a really encouraging phone call, saying they'd gone through the same thing in the '80s," Fanton said. "He said they eventually learned not just to think about world betterment, but also to take time for themselves, and that was their turning point. Now, they're a solvent and robust organization again. I really needed to hear that."

"As a charitable foundation, we can do a lot of good in the world," Fanton added. "We just need to make sure not to do too much good at once."