Jamie L. Whitten, 85, a retired Mississippi Democrat who chaired the House Appropriations Committee and served longer in the House of Representatives than anyone in history, died of heart and kidney ailments yesterday at a hospital in Oxford, Miss.

The last of the Democratic grandees from the South who once exercised enormous influence on Capitol Hill, Mr. Whitten was a survivor of the Great Depression, an unreconstructed New Dealer who believed in federal programs to promote the well-being of his constituents. He was a former segregationist who became a moderate on civil rights, a chief architect of the nation's agricultural policies for nearly half a century and a master of legislative strategy and tactics.

He won a special election in 1941 and took his seat in Congress a month before the Japanese attack on Pearl Harbor on Dec. 7, 1941, brought the United States into World War II. On Jan. 6, 1992, he broke the record for service in the House set by Carl Vinson (D-Ga.) between 1914 and 1965. A month later, he suffered what was reported to be a stroke.

In 1947, Mr. Whitten became chairman of the agriculture subcommittee of the House Appropriations Committee. He was elected chairman of the full Appropriations Committee in 1979.

Except for the years 1953 to 1955, when Republicans controlled the House, he headed the subcommittee until 1992, when he was ousted by members concerned about his failing health. He lost the chairmanship of the full committee at the same time. On April 5, 1994, he announced he would not seek another term, and he retired at the end of the year.

Although hardly a household name, Mr. Whitten became one of the most powerful members of Congress through his subcommittee chairmanship. It gave him enormous power over farm programs and earned him the nickname of "permanent secretary of agriculture."

The subcommittee also handled projects ranging from waterways and roads to crop subsidies and "dire emergency" spending bills to assist farmers in trouble. Those measures were vitally important to many members representing constituents far beyond Mr. Whitten's 1st Congressional District in northeast Mississippi, and his control over them was a principal source of his influence.

A theme that guided Mr. Whitten throughout his career was that the wealth of the nation is measured in physical assets rather than money. Although he was a fiscal conservative, that theme translated into unapologetic support for what some might call pork barrel projects.

In his own district he sponsored the Tennessee-Tombigbee Waterway to provide a direct link between the Tennessee River and the Gulf of Mexico. Completed in 1985, it has never reached the levels of traffic that were projected to justify its cost. He also successfully backed a much-criticized advanced solid rocket motor project, which is in the town of Yellow Creek in his district. The cost has been estimated at $3 billion.

"My district is part of the nation," Mr. Whitten used to say. "And if you handle a national program and leave out your district, you would not want to go home."

Jamie Lloyd Whitten was born April 18, 1910, on a farm in Cascilla, Miss. His relatives were farmers. He graduated from the University of Mississippi in 1927. He was a teacher and school principal for a brief period and then became a lawyer.

He was elected to the Mississippi House of Representatives in 1931. Two years later, he was elected district attorney for the 17th Judicial District. He was chosen for Congress on the strength of his record prosecuting gamblers who had been run out of Memphis by E.H. Crump, the famous political boss.

Mr. Whitten was a foe of the civil rights movement. In 1956, he signed the Southern Manifesto, which attacked the U.S. Supreme Court's decision in Brown v. Topeka in 1954 that outlawed segregated public education. Through the 1960s, he voted against civil rights legislation and also opposed Medicare and poverty programs.

In later years, he backed the goals of the national Democratic Party even when they were unpopular with some of his constituents. He was mindful that African Americans accounted for 23 percent of his constituents. In none of the 26 elections that he won did he ever receive less than 59 percent of the vote.

"Conditions change," Mr. Whitten said in an interview. "You go with conditions as they are, not like what they used to be."

In the 1970s, Mr. Whitten angered many liberals with his opposition to regulations to control pesticides and other environmental measures. In 1978, efforts were made too block his accession to the chairmanship of the Appropriations Committee, but House Speaker Thomas P. "Tip" O'Neill (D-Mass.) was on his side and overrode the opposition. Mr. Whitten, in turn, supported food stamps and other programs important to O'Neill.

Mr. Whitten, who lived in Charleston, Miss., is survived by his wife, the former Rebecca Thompson, and two children, Jamie L. Whitten Jr., a Washington lawyer, and Beverly Merritt of Arlington, Tex.