HE'S SERVED AT MORE White House state dinners than any president has hosted, but tonight, for the first time in 44 years, John Ficklin will be sitting down as a guest.

In fact, at tonight's dinner for the amir of Bahrain, Ficklin, 64, the son of a Virginia slave, will be sitting with the first lady rather than escorting the president to his seat.

Ronald Reagan is the last of nine presidents Ficklin has served since he started out in 1939 as a part-time pantry man. Six weeks ago he retired as maitre d'hotel, bringing to a close a career that spanned a thousand moments of behind-the-scenes history and intimacy that even the closest White House aides rarely witness.

As the first person they saw in the morning--over breakfast--and sometimes the last person they saw in the evening before retiring, Ficklin was given a view of real people, not the polished products of paid image makers.

Harry and Bess Truman, for instance, treated him like one of the family. Jacqueline Kennedy chose him to be among the close friends who ushered at John Kennedy's funeral. Two days before the rest of the world knew, Ficklin said, he was told that Richard Nixon was going to leave and that he should be ready to start the packing.

He still hears from Nixon at Christmas, just as he does from Gerald Ford and Jimmy Carter. They meant something to him while they were at the White House.

"You hate to see them leave, yet you know they have to because someone else is coming in. And then you hate to see them leave, too. That's life," said Ficklin, sitting in his Northeast Washington living room with his wife, Nancy.

He was one of 10 children and came to Washington from Amissville, Va., at the age of 15 "to get out of the country." He went to work at a Silver Spring riding school and later as an office boy for a dentist. Though his brother Charles worked as a White House butler (and was Ficklin's predecessor as maitre d'), it never occurred to him that his own path would one day cross those of most of the major political figures of mid-20th-century history.

Ficklin never kept a diary--"things I've read that some people have written, I don't know how they had time enough to hear and still be doing their jobs." But his memory is vivid and his recollections reveal that presidents and their families at home are pretty much like other mortals. For example:

* Harry S Truman knew everybody's name at the White House and took such a personal interest in the staff that he'd even sneak into the hospital if they were sick.

* Dwight Eisenhower, who loved to cook and often spent two days making a pot of soup, personally went over each day's menus and guest lists at breakfast.

* Lyndon Johnson was such a night owl that a late shift had to be added to the White House staff's day.

* Truman and Eisenhower served rum-laced punches, never mixed drinks, in the State Rooms, a tradition John Kennedy broke and Johnson, Nixon and Ford continued to break. Carter brought back those somewhat abstemious times when he served only wine, to everybody's surprise but Ficklin's.

Ficklin's first encounter with a president occurred his first day on the job when he'd been called in to work a press party Franklin Roosevelt was giving. When Ficklin and a coworker carried a large vermeil candelabra onto the elevator, who should be seated there in his wheelchair but FDR?

"Welcome aboard," the president told the astonished young man as introductions were made.

After that, Ficklin was called back numerous times to work in the pantry washing dishes and shining the silver for luncheons, receptions and dinners. The Roosevelts sponsored a series of war relief teas at embassies around town, and Ficklin was often on hand.

In 1941 he was drafted and served in the Army medical corps in the South Pacific. Back home in 1946, he had a chance for a job with the Veterans Administration for $1,420 a year and one at the White House for $1,460. He took the latter because it meant he wouldn't have to run back and forth between Washington, where he lived, and Maryland, where the VA job was.

He met the Trumans his first full day on the job when he served them all breakfast. That meal became the time of day that the Trumans caught up on everybody's lives. Once, when Ficklin worked his own shift as well as his brother's, Bess Truman asked him, "John, didn't I see you this morning? Who's off?"

When Ficklin told her it was his brother Charles, who was ill, she asked the White House physician to check him over. He had pneumonia. He went into the hospital and a few days later Harry Truman sneaked out to see him.

"He walked up the back steps and right into the room. There were no nurses, no doctors, nobody but in there but the president," said Ficklin.

Another time, when John Ficklin was ill, the phone rang at home and Nancy Ficklin heard a woman's voice on the other end say, "This is Bess Truman . . ."

It was when Eisenhower was president that Ficklin and the other butlers were first paid for working overtime. Work days often went from breakfast straight through to midnight if there was a state dinner. At the White House the term "butler" was associated with serving food but also with just about anything a president or first lady wanted done.

"You just can't put down on paper everything that a butler would do," said Ficklin, who became head butler under Eisenhower. "Instead of calling someone and saying the president or first lady wants such and such, you'd just go do it yourself."

From the moment he saw Walter Cronkite, tears streaming down his face, tell a nationwide television audience that Kennedy had been assassinated, Ficklin decided he couldn't go home because as head butler it fell to him to supervise the others. "I just took it upon myself to stay because I realized that being the boss, I did more brain work but less manual labor. So I'd let them go get some sleep."

Nobody quite knew what to do or where to turn until Jacqueline Kennedy, wearing the same blood-spattered suit the staff had seen her in throughout the day on television, returned to the White House. She called everybody by name but made no immediate decisions.

"The children were upstairs asleep. I guess she told them the next day because she just wanted to be left alone," said Ficklin. "In the morning things started to come together. Then the night before the funeral we were preparing to feed all those kings, presidents and prime ministers when Mr. West J.B. West, then chief usher told me that Mrs. Kennedy wanted me to be an usher at the church."

Ficklin said he balked at first. Besides supervising the permanent staff of butlers and pantry people, there was all the extra help coming in to serve at the post-funeral buffets. Also, he didn't have a morning suit. The White House solved that by getting the owner of a rental store out of bed to alter a suit for Ficklin by 7 the next morning.

Ficklin became maitre d'hotel of the White House in the Johnson administration, responsible for a full-time staff of 14 butlers, pantry men and maids and their payroll.

Throughout the years, few if any whites have been on the butlery staff. "A lot of them didn't want that type of work," said Ficklin. "We got quite a few applications, but when it came down to really working, they weren't very interested."

Ficklin said he always got along all right with Lyndon Johnson but there wasn't much anybody could tell him that he didn't already know. When daughter Luci married Pat Nugent, Johnson wanted to be right up there helping her cut the wedding cake.

Ficklin said Johnson didn't want anyone to tell him how to do it so there wasn't any chance to let him know that he was cutting the wrong layer, the one bakers make of cardboard to support multitiered cakes.

"I think Luci had to show him," said Ficklin.

Johnson could be a bully without much provocation, from the sound of Ficklin's reminiscences. A butler who dared to pour him a highball using a second serving from a just-opened bottle of soda water might be ordered to taste it himself. Or a butler who accidentally made a noise while LBJ was presiding at something might be reminded of it later.

"You hear all that noise in the dining room last night?" Ficklin said LBJ asked his Cabinet officers one day. Then, pointing to the butler serving them lunch, "Well, he's the one who did it."

But there were relatively few mishaps through the years, considering the thousands of events and people that kept Ficklin and his staff busy. Once, a part-time butler lighted a fire in the State Dining Room without realizing the fireplace was nonworking. Smoke began rolling forth, male guests rushed to open the windows and the late Marjorie Merriweather Post yelled for everybody to hear, "Oh, my God, the Lincoln portrait is ruined!"

It wasn't, according to Ficklin. The next day, someone was called in to wipe the smoke off.

Ficklin's White House responsibilities didn't leave much time for a private life.

"To tell you the truth, there hasn't been much family life. Vacations were about the only time, or when the president was away. I was on 24-hours call," he said.

None it ever much bothered Nancy Ficklin, their sons J. Woodson, 31, and John Wrory, 27, or Ficklin, who's something of a hero back home in Amissville. In fact, left over from a party for him on his 25th anniversary at the White House, there is a sign that hangs in Ficklin's family room.

It reads: "Amissville Kid Makes Good!"