Mr. Gelbaum began contributing $50,000 or so annually to the A.C.L.U. in the early 1980s and kept increasing his gifts, to $22.5 million in 2008, board members said.
The only condition he placed on the gifts was that he remain anonymous, so only a handful of people at the A.C.L.U. knew he was the donor. ... Mr. Romero did not reveal Mr. Gelbaumâ€™s name, describing him only as â€?a donor,â€? board members said
Still, it is hard to keep secrets with a board of more than 80 members, most of whom report to state affiliates. â€?As soon as he started telling us, anyone who had a laptop with them was busy Googlingâ€? and figured out who the donor was, a national board member said.
Mr. Romero told the board that the donor had also stopped giving to three â€?sister organizations,â€? a phrase board members said he had used in the past to describe other groups with which the A.C.L.U. has collaborated, like the Sierra Club.
Mr. Gelbaum took a rare turn in the spotlight earlier this decade when environmental activists said he was behind the Sierra Clubâ€™s decision to adopt a neutral stance on immigration. Some people believe immigration has aggravated environmental problems.