Albert L. Nellum, who founded A.L. Nellum and Associates in 1964 and operated the consulting firm until he retired in the early 1990s, died March 1 at the Heritage Hall health-care and rehabilitation center in Leesburg, Va. He was 81.

The cause was Alzheimer’s disease, said his daughter, Rebecca Nellum Williams.

Jet magazine described Mr. Nellum’s business as “the country’s oldest black-owned management consulting firm,” and Black Enterprise magazine named it one of the top 100 black-owned businesses in the United States. Mr. Nellum maintained offices in several cities and his clients included federal and D.C. agencies.

Mr. Nellum also helped found and lead the national Black Business Council. He traveled frequently to Japan to promote business and cultural ties and to improve race relations.

Albert Lamar Nellum was born in Greenville, Miss., and grew up in Chicago. He was a 1954 graduate of Loyola University Chicago. He served in the Army from 1955 to 1957.

Early in his career, he served on the staff of Chicago’s Youth Commission and on the board of the Catholic Interracial Council, also in Chicago. He later worked in the Labor Department during the Kennedy administration.

Mr. Nellum held leadership positions with the Congressional Black Caucus Foundation and helped launch initiatives including a regular fundraising dinner, his daughter said. He also hosted events to honor distinguished African-American actors.

He served on the boards of organizations including the Martin Luther King Jr. Center for Nonviolent Social Change. His honors included the Martin Luther King Jr. Distinguished Service Award and NAACP Image Award, his daughter said.

Mr. Nellum was a District resident before moving to Reston, Va., where he lived for three decades. He led fundraising efforts at St. Augustine Catholic Church in Washington.

His marriage to Judith Rolston Nellum ended in divorce. His wife of 26 years, Velma Love Nellum, died in 2010. Survivors include two children from his first marriage, Rebecca Nellum Williams of Ashburn, Va., and Daniel A. Nellum of Crofton, Md.; a stepson, Brian K. Stewart of Ashburn, Va.; a sister; and eight grandchildren.

— Emily Langer