The Plainsfolk, who earlier had established a beachhead at the Ambassador Hotel and forayed later to the Armory itself (where President Carter presided over an Inaugural ball) fanned out yesterday to some of the capital's most sacred monuments before withdrawing, last night, back to Georgia.

"Were you in danger at all times?" the Yankees tended to ask those who had actually viewed the citizens of Plains. Carter's home town and a peanut center of 600 inhabitants.

The 350 or so Georgians, for their part, were too polite to say they had found the capital more alarming than the Danish invaders ever found England. First, half of them found their hotel reservations meant nothing, and were stranded without rooms. Others found their rooms unbearably hot.

Still others found their rooms like ice. Sometimes buses they had counted on did not show up. There was ice on walkways - examined with some interest as well as panic by the Georgia ladies - and most of them saw hardly anything of the swearing-in or the parade because of the crowds.

Nevertheless, five or so full bus-loads of them set out again yesterday to do battle with the capital and vieiw its monuments, now that Georgians feel safe this far north.

"There is everybody's favorite building," said the guide, "the Internal Revenue Service."

Few could be found in laugh.

Then the group toured the Bureau of Engraving and Printing and saw endless money being printed and stacked. "Naw, I didn't get a sample," a wit said.

The guide said the cathedral was right there to the right. "That is a gas station," said a Georgia authority correctly.

At the Lincoln Memorial, some of the older visitors heard there were 58 steps, one for each year of Lincoln's life.

"Fifty eight steps, " gasped one woman. "Did you hear that?" Southerners, as the capital will soon learn, would rather be fried in peanut oil than go up steps, so several remained in the buses.

The ones who walked into the shrine did not oblige their observers by saying beautiful things.

At the Jefferson Memorial, it was the same.

Some took pictures, but the great flurry of cameras popping occurred at the Watergate Apartments. All persons at windows had the weight of at least one Georgian on him going click-click with an with an Instamatic.

The Georgians were bandbox fresh and trim, possibly because they were going to a White House reception after the tour.

To be beautiful you must suffer.

"My room was real warm," said Walter Davenport, a 27-year-old farmer of Plains (peanuts, soybeans, corn, Hereford and Angus cattle), but I did notice the linen hadn't been changed, and there weren't enough towels."

(This was partly because the Georgia women had all washed their hair and generally got themselves up fit to kill to attend a presidential ball.)

"Fuses kept blowing," Davenport said. "I was in the shower when the lights went out. I didn't have a dry towel and had quite a time" finding clothes, etc.

"My wife made seven different decisions what to wear," he said, "but of course did not wear any of those things."

The invaders, apart from melodious soft voices (something should be said some day how it hurts the Southern ear to be assaulted throughout most of the rest of America with loud honks and whines passing for speech) were like other Americans. There were a number of mink jackets, sparkling white shirts, and all God's chillun had shoes.

One of the Plains people was David Wise, who has moved to Miami and become a veterinarian dealing largely with dogs.You cannot assume that because they all wear the label "Plains, Ga.," that they have never gone to school or never got past arm's reach of redeye.

Harold Isaacs is a professor of history from Americus. He said the Carter campaign and the train up to Washington had been a restorative and healing force within Georgia itself - like New York, Georgia has many layers and constituencies and classes and tensions.

Chris Spann of Plains, in the auto and tractor parts business, is a bridegroom of two weeks. He stayed on the bus and did not seem particularly interested in the monuments. His wife did not miss a one.

Davenport now farms on about 600 acres. He started renting a little land and it went okay, then he went farther into farming on his father's place and now he runs it. Georgia farmer, yes. Small town, yes.

But before any big-city guy gets too smart, Davenport might point out (though he didn't) that it's a lot easier to get clean in Plains than in Washington, and down there they are way ahead of us fuse-wise.