Catroppa, 63, will officially retire Tuesday after serving as superintendent for eight years. The historic site in downtown Atlanta showcases the life of the slain civil rights leader and the civil rights movement.

During his tenure, Catroppa has nearly doubled annual attendance, in part by bringing in provocative exhibits such as the current one: "Of Ballots Uncast: The African-American Struggle for the Right to Vote." Catroppa also guided the ongoing $4.2 million renovation of Ebenezer Baptist Church, where King was pastor; commissioned a transportation feasibility study for Atlanta tourist attractions; launched the International Civil Rights Walk of Fame at the site and forged a strong relationship with the city's civil rights community.

"I think Frank is an unsung hero of our community," said A.J. Robinson, president of Central Atlanta Progress, which awarded Catroppa its 2005 Community Leadership Award. "He is really a treasure in terms of what he has done for us and the whole community in preserving that whole part of Atlanta's history."

Catroppa's retirement comes just when the Park Service is negotiating to buy the Martin Luther King Jr. Center for Nonviolent Social Change from the King family, which would expand the government's presence. But he seems content with his decision to leave the Park Service after 32 years, 25 of them in the agency's Southeast Regional Office in Atlanta.