NAACP President Kweisi Mfume (search) said Tuesday that he's stepping down as the head of the nation's oldest and largest civil rights group to spend more time with his family.

The organization's legal counsel, Dennis Hayes, will serve as interim president while a national search is conducted.

"For the last nine years, I've had what I believe is both the honor and the privilege to help revive and to help restore this great organization, which has ... really become an American institution," Mfume said.

Mfume said that he had no immediate career plans. "I just need a break. I need a vacation," he said. "I'm just not going to do anything for a while."

Mfume said "in my heart of hearts, I know the job has been done, and I step aside willingly ... to find another challenge and another chance to make a real difference."

Shortly before his public announcement, Mfume said he received a phone call from senior White House adviser Karl Rove (search) who extended best wishes on behalf of President Bush, who is traveling.

He also spoke with other civil rights and political leaders, including Maryland Lt. Gov. Michael Steele, a Republican who is African American, and Jesse Jackson, head of the Rainbow PUSH organization.

Reached by phone in Philadelphia, Jackson told The Associated Press that he's known the outgoing NAACP president since early in his career, including when Mfume worked as a local organizer on Jackson's presidential campaigns in the 1980s.

"Each place he left, he left better off. He came at a time when the organization needed morale and credibility, and he brought both," Jackson said.

Mfume, 56, has been president of the Baltimore-based National Association for the Advancement of Colored People (search) since 1996.

He inherited an organization tarnished by scandal and burdened by a $3.2 million debt and is credited with helping steer it into an era of stability and growth by instituting corporate-style management techniques.

Mfume, whose adopted West African name translates to "conquering son of kings," began his career as a dashiki-clad popular radio talk show host and political activist in the 1970s. He transformed himself into one of the nation's foremost civil rights leaders with a reputation for bridge building.

"To serve as the president of the NAACP ... clearly has been the most rewarding and the most fulfilling experience in my life," Mfume said. "I walk away with more rather than less."

He served on the Baltimore City Council from 1979-1987 before winning a closely fought race to succeed former congressman Parren Mitchell as Maryland's representative from the Seventh District. Mfume served five terms in Congress and was leader of the Congressional Black Caucus before stepping down to head the NAACP in 1996.

But in recent months, relations between the NAACP and the White House have grown strained.

Last month, the organization's chairman, Julian Bond (search), announced that its tax-exempt status is under review by the government in an investigation he contends stems from a speech he gave that criticized President Bush. Bond said IRS agents were investigating his keynote address July 11 at the NAACP's annual convention in Philadelphia.

For an organization to keep its tax-exempt status, "leaders cannot make partisan comments in official organization publications or at official organizational functions," according to an Oct. 8 letter to the NAACP from the IRS office in Louisville, Ky.

In September, the group launched a national billboard advertising campaign aimed at combating what officials describe as slowing membership growth.

The civil rights group, founded in 1909, wants to increase membership by 20 percent, Mfume said at the time.

The group claims 500,000 members, but it has not seen significant membership growth in recent years.

Also in September, Mfume apologized to U.S. Education Secretary Rod Paige, whose invitation to speak at an Ohio NAACP dinner was withdrawn. Mfume said he was "appalled" when he found out about the snub.