Cardinal James A. Hickey, former archbishop of Washington, who led the Roman Catholic Church in the nation’s capital for two decades, died yesterday. He was 84.

One of 13 Americans in the College of Cardinals, Hickey headed the Washington Diocese from 1980 to 2000. He died in a Washington nursing home after “his health slowly deteriorated over the past year,” said Susan Gibbs, the spokeswoman for the diocese.

Born October 11, 1920, in Midland, Mich., Hickey was ordained a priest 58 years ago and became a cardinal in 1988, eight years after he became archbishop of Washington. On his selection as cardinal, Hickey expressed humility and appreciation to the pope.

“In the years remaining for me, I shall strive to be a caring pastor, a faithful teacher, a loving father and brother, and a true servant of the people of God in the District of Columbia and the five counties of Maryland,” Hickey said at the time. “I am truly honored, very humbled, and deeply grateful that our Holy Father, Pope John Paul II, has chosen me to serve as a cardinal of the church.”

Cardinal Theodore McCarrick, the current archbishop and Hickey’s friend for more than 40 years, said Hickey’s death was a “poignant loss for the church of Washington and a personal loss for me.”

Hickey came to Washington with a reputation as an activist priest. He became a crucial figure in dealing with the government on issues affecting the church in Central America.

Two of four nuns murdered in El Salvador in 1980, the year Hickey was brought to Washington, had been under his jurisdiction as bishop of Cleveland, and he had ridden in the van in which they were murdered.

President Reagan’s secretary of state, Alexander Haig, said the four nuns were trying to run a roadblock when troops of El Salvador’s right-wing government shot them. A 1993 U.N. report on human rights abuses by that earlier Salvadoran government called Haig’s statement “totally outrageous.”

Also in 1980, Hickey attended the tumultuous funeral of his friend, assassinated Salvadoran Archbishop Oscar Romero, whose death precipitated a 12-year civil war that ended in 1992.

Hickey began his activist career ministering to immigrants in the Saginaw, Mich., area, said Hickey’s longtime secretary, Monsignor Kevin T. Hart. “He will be remembered for his work with the poor,” said Hart, pastor of St. Ann’s Catholic Church in Washington.

Hickey lobbied for increased spending to aid the poor, tried to persuade members of Congress to stop giving aid to the Nicaraguan Contras in the 1980s, and pushed for bishops to take strong stands in favor of nuclear disarmament and against increased military spending.

Church people considered Hickey farsighted in dealing with abusive priests, a problem that grew rapidly around the country during his tenure in Washington.

Among his innovations were establishment of a review board and a policy not to return abusive priests to ministry.

Often described as a conservative on church issues despite his social activism, Hickey expressed compassion when a priest in his diocese died of AIDS in 1987. Little was known then about the disease except that it was transmitted through intimate sexual contact, infected needles used in illegal drug use, or contaminated blood transfusions.

Hickey said he encouraged the Rev. Michael R. Peterson to disclose his illness because he wanted to demonstrate that compassion for AIDS patients was as much a part of church teaching as its rejection of homosexual relations. He said he never asked the priest how he contracted AIDS.