They were Jimmy Carter's legions who had marched with him from snow to snow. And yesterday they reached the White House.

They came by the busloads, represented every state in the union, carried their coats since there was no place to check them, clutched cameras, every baby strollers, and in one footsore woman's case, shoes, to file through seemingly endless linesd to meet the man they helped make President.

"These are the folks who two years ago took me into their homes and their neighbours laughed at them." said Jimmy Carter of the first reception group of 1,000. A note of satisfaction was discernible in his voice.

"It's an emotional day for me." said Rosalynn Carter, who, at ease in her hour of triumph, stood at his side to receive more than 4,000 old friends, new friends. Inaugural committee workers, governors of the 50 states, leaders of labor and business and alumni from Carter's Peanut Brigade.

"It is," said Mrs. Robert E. Lines of Decatur, Ga., tears swelling in her eyes as she craned her neck for a final glimpse of the Carters standing in the Great Hall beneath the Presidential seal." the greatest day of my life."

It was a day of spontaneous warmth, demonstrative hospitality, disarming informality and requited affection.

"I love you. I love you." Carter told a sextette of women from the Garden Club of Georgia who, in 26 hours beginning at 1 p.m. Wednesday, had festooned the State Rooms with 70 floral arrangements blooming with more than 700 dozen varieties. "Your flowers meant a lot to all of us.

He was President, host, heead of the family, organizer.

"Let's go listen to the music," he said to his wife, after shaking hands with U.S. Governors, Cabinet Officers, their wives and some of their children. They listened intently as the Cleveland Quartet played a selection by Beethoven.

"I went through the receiving line," said Carter's aunt "Sissy" Colvin of Roswell, Ga., "and he said get out of this receiving line and get over there and start meeting these people."

She did, as did Carter's mother, sons, daughters-in-law, aunts, cousins, children's in -laws-virtually the entire Carter family except for daughter Amy and brother Billy. They hugged, squeezed, patted, kissed ("Everybody is kissing today," said a cousin.)

There were reunions, in a sense, everywhere. Dr. and Mrs. Edmund Cain of Reno fondly greeted Judy and Jack Carter who had stayed with the Cains "back before the Nevada primary. I was one of the first people on the bandwagon,." said Virginia Cain. "The reason was I felt America needed moral leadership badly."

Washingtonians Bruce and Joy Sundlun were others who had given the Carters a bed. To prove it ever after, the Sundluns-and everyone else who had been hosts on overnight visits-were rewarded upon arrival with an engraved copper plague that read:

"A member of the Jimmy Carter family stayed in this house during the 1976 Presidential Campaign."

"We'll hang it over the bed," announced a jubilant Sundlun.

"Miss Lillian" Carter, the President's mother, complained of "sore hands and sore feet," begged off autographs ("All we Carters bruise easily," said sister Ruth Carter Stapleton) but generously bestowed smiles as she stood in the path of guests exiting through the North Portico.

The Queen's Bedroom (Rosalynn Carter's mother, "Miss Allie" Smith slep in the Lincoln Bedroom) was unimpressive, Miss Lillian said, "no different from mine-it wasn't as comfortable,"

If Miss Lillian's tales of the previous night sounded as if she had 'done" the town until 3 a.m., grandson Jeff's went her one better. "I haven't been to bed yet," he said at 10 a.m., five hours after he and his wife arrived back at the White House from a post-inaugural - and apparently all-night - party.

Inaugural parties, in fact, were still on the minds of his elders.

"I just went from one party to the next," joked Vice President Walter Mondale following the Governors' Reception, "then came right over here."

"I heard on the radio you were up late," Rosalynn Carter told him.

"Well, if Washington is like this all the time," said Jimmy Carter, "no wonder Jeff likes it."

Joan Mondale was nice to dance with, he said gallantly. "Rosalynn's got soft feet," replied Mondale. "I know because I stepped on them."

Mrs. Carter laughed politely, "I couldn't get my shoes on this morning." she said.

"The Mondales assisted at three of the our receptions when welcoming the governors, they stood with the Carters in the blue room and at the other two at the doorway to the State Dining Room which became the final lap in the receiving line sanking its way to the Carters.

For the first and fourth receptions, those entertaining Carter family hosts and members of the Peanut Brigade, chartered buses carried guests from a staging area at Fort McNair. Alighting at the Diplomatic Entrance, guests picked up their engraved invitations at tables in the cross hall (aides said that to have mailed them before Carter was sworn in would have been "inappropriate") and were then channeled to the State Floor above.

Altogether, 73 busloads of people were moved to and from. And at one of the afternoon parties, 70 gallons of fruit punch were served.

One guest accorded quasi-official attention was Mexico's First Lady Carmen Romano deLopez Portillo, escorted by Chief of Protocol Shirley Temple Black. At her husband's inauguration in December, he, too, took the walk among the people.

"Spontaneous," she said through an interpreter, when asked if he had informed his security agents in advance. "Both men think in the same way-they have a great desire to live together and with the people."

The second reception of the day drew the governors, some enthusiastic about a Democratic President in the White House (My heart is now warm." said Kentucky's Julian Carroll, who second governor in the United States to announce for him.") some not ("I'd rather have had Ronald Reagan," said New Hampshire's Meldrin Thompson).

Alabama's George Wallace had no advice for Carter, he told reporters later. "I just told him I was happy for him. I wished him well and I 'm happy to see him in the White House."

When the Democratic National Committee arrived at a reception for its members and leaders of labor, business and stars of the Inaugural Gala, Robert Strauss was first in line.

"It's nice to lead the Democratic party into the White House," said the former chairman. "It's a great day for America and a very emotional one for me."

Tempers were even, expectations bright as the crowd of familiar and unfamiliar faces inched slowly, towards the day's denouement.

There had been Luci Nugent, Loretta Lynn, Muhammad Ali, James Dickey, Averell Harriman, Ruth Warwick, a star on Miss Lillian's favorite soap opera, "All My Children." Hank Aaron guessed he and his wife had waited "maybe 15 minutes, but it was worth it."

Shirley MacLaine thought it was longer.

Eight years," she said.