Samuel C. Jackson, 53, a Washington lawyer who was respected for his knowledge of corporate law, a supporter of civil rights and minority causes, and a Republican from Kansas who held high office under presidents Johnson and Nixon, died of cancer Monday at Sibley Memorial Hospital.

Mr. Jackson, who had been a resident of Washington since 1965, was active in GOP politics on the local and national levels. Friends and associates said his approach to these endeavors, unlike some of his contemporaries, was to work from within organizations rather than meeting them in open confrontation.

Thus, in 1972, he helped organize and became chairman of the Black Council, a group of 40 top-level black government officials opposing a constitutional amendment to curb school busing. Because of his work through this organization and other activities, he was credited with having played a substantial role in persuading the Nixon administration to temper its opposition to school busing before the 1972 elections.

He also was a founder of the Council of 100, a national group of black Republican businessmen that has been influential in Republican politics.

In January 1981, President Reagan named him to the Blue Ribbon Commission on Housing, where he is said to have been an advocate of public housing programs.

As a resident of Washington, Mr. Jackson was a key supporter and campaign official for the Rev. Jerry Moore in 1974 when Mr. Moore, a Republican, first was elected to the D.C. City Council. In 1980, he was a D.C. delegate to the Republican National Convention and a backer of George Bush for the presidential nomination.

On hearing of his death, Vice President Bush said he was "deeply saddened by the loss of a good friend and an outstanding business and political leader who had done much for the Republican Party and to further the concept of two-party government among black Americans."

Benjamin Hooks, the national president of the NAACP, said, "It was my privilege to know and work with Mr. Jackson for almost 20 years. He was the type of black Republican that all blacks can be proud of. We shall miss this gallant warrior, especially at this critical time in our nation's history."

A speech Mr. Jackson made to a civic group in Reston in 1970 is characteristic not only of his independence as a Republican, but of his view of how to be effective in public life. He told his audience that he had decided to address them rather than attend a highly publicized rally organized by the Southern Christian Leadership Conference in Atlanta "because the problem is here in comfortable suburbia, white America."

"Just as enlightened leadership is essential at the local level," he said, "so will the frustration and division throughout the country be ended only by a national leadership whose commitment to social justice can clearly be seen in both its words and its deeds.

"People are dying in this country today. They die trying to make someone listen to them about the war, about poverty, about powerlessness, about injustice."

Mr. Jackson's own national service began in June 1965 when President Johnson appointed him one of the five original commissioners of the U.S. Equal Employment Opportunity Commission. He served three years. From 1968 to 1969, he was vice president of the American Arbitration Association and director of its Center for Dispute Settlement.

In 1969, President Nixon named him assistant secretary of Housing and Urban Development for metropolitan development, the third-ranking official in the department.

Mr. Jackson helped develop and implement basic policies for the federal government's housing and planning programs. He also served as general manager of the New Communities Development Corporation.

In 1973, he resigned to become a partner in the Wall Street law firm of Stroock & Stroock & Lavan. He practiced in its Washington office until his death. His specialty was corporation law.

Throughout his legal career, Mr. Jackson, like many of the best members of his profession, found time to serve community interests as well as those of his clients. He had been a national trustee of the NAACP special contributions fund since 1968 and was a former NAACP board member and a member of its national legal committee.

Other clients outside of his corporate practice included Operation PUSH, the self-help organization founded in Chicago by the Rev. Jesse Jackson, and the Church of God in Christ, of which he was general counsel and a lifelong member.

Mr. Jackson was born in Kansas and earned bachelor's and law degrees from Washburn University in Topeka. He served in the Air Force, directed the Topeka office of the NAACP and was deputy general counsel of the Kansas Social Welfare Department. He moved to Washington when Johnson appointed him to the Equal Employment Opportunity Commission.

One of the first civil rights cases on which Mr. Jackson worked resulted in the landmark 1954 Brown v. Board of Education decision, in which the U.S. Supreme Court held that segregation in public schools was illegal.

Mr. Jackson's survivors include his wife, Judith, of Washington; two daughters, Brenda, also of Washington, and Marcia Sandels of Topeka, and seven brothers and sisters.