In a week of hopes, history and hoopla, the talk of the country was the same as the talk of the convention of Alpha Kappa Alpha, the black women's sorority that last night celebrated its week-long convention with a banquet that may have been the biggest the nation has ever had.

They had linked arms yesterday with the Rev. Jesse Jackson on the west steps of the Capitol, and last night they heard vice presidential candidate Rep. Geraldine Ferraro (D-N.Y.), and all week they'd worried about the scandal surrounding Vanessa Williams, the first black Miss America, and the first Miss America to be asked to resign.

But the tone was optimistic as thousands of sorority sisters sensed they may well be closer to the center of American concerns now than ever before.

Said Ferraro to about 8,000 cheering AKA members and escorts: "I am proud to say that the 'White Males Only Need Apply' sign is no longer posted outside the White House."

Though many of Ferraro's words were lost in the massive convention hall, there was loud applause when she said: "Until every American can dream of growing up and being president, our dream is not complete."

C. Elizabeth Johnson, 80, a retired librarian from St. Paul, Minn., put down her fork when Ferraro ended her brief remarks.

"She's a beautiful woman, I wouldn't say she can talk like Jesse, but she did her homework," she said. Johnson had changed into a long, light green gown since the Jackson rally. With her brown eyes flashing over her silver-framed glasses she added, "You know, I feel like dancing. This is a truly great day."

Then, after announcing that she was speaking for the entire table of AKA members, all of whom wore pearl crowns signifying that they were celebrating at least 50 years in Alpha Kappa Alpha, Johnson said, "We can't afford to be tired. We have to work hard to get that man who's in the White House out."

Another crowned AKA member at a different table shared Johnson's views on Reagan but was much more cautious about Ferraro and the Equal Rights Amendment.

Said Margaret Smith, a retired educator from Hampton, Va., "I expected Ferraro's feminist viewpoint, but, frankly, I am not for ERA. I have gotten this far without it, thank you, I don't see why we are asking for equality of women instead of equality for people."

Earlier, in the near-90 degree heat of noon on the west steps of the Capitol, Johnson had been one of a huge crowd to link arms with Jackson as he told their voter registration rally:

"Women can take a little and do much. I know, I was raised by my mother and my grandmother."

Then, referring to Ferraro, Jackson added, "Women, your time has come!"

He's the closest thing to Martin Luther King that we have," said Johnson. "And I should know. King was my pastor in Montgomery, Alabama."

Johnson said she walked the two miles from the convention center, where most of the sorority's activities have taken place, to Capitol Hill to hear Jackson. "He's only young yet, but you'll see, he'll be another great one."

"I love that man," said Maryle Wilson, a gray-haired AKA member from Pasadena, Calif., who helped register more than 200 new voters at home. "He's my candidate."

"All right, Jesse," someone shouted from a crowd that police estimated at between 8,000 and 10,000. Almost all wore the sorority's bright colors, pink and green.

Said Wilson, "Can't you just feel Jesse's charisma? He energizes people."

Wilson, 58, a retired physical therapist who now teaches exercise classes to the elderly, acknowledged that the AKA members were not part of the "locked-out" constituency that Jackson had spoken about at the Democratic convention and during his campaign.

"But you know," Wilson said, "the issues of the black middle class are really the same as the poor. I have two children and it was harder for them to get jobs than the white students they went to school with."

Wilson is one of 75,000 AKA members nationwide who, in addition to organizing voters, devote time to programs for the poor.

"Things haven't changed all that much," she continued. When she first began working at a Los Angeles County hospital, she was the only black physical therapist on a staff of 200. "When I left three years ago, I still was."

"The Reverend Jackson would be the perfect ambassador," said Caroline Lattimore after Jackson finished. Lattimore, the national chairwoman of the AKA committee that organized the voter registration drive, said, "He has a gift for people. He is a natural leader."

Lattimore sat behind Jackson as he spoke and later said she had promised him that her group would try to add "another 20 percent by November" to the 242,000 voters AKA has registered during the past year.

After the crowd fled the hot sun, the undergraduate sorority members boarded buses that took them to the Sheraton Washington, where Suzette Charles sang as part of the luncheon entertainment.

Charles assumed the Miss America title Monday when Vanessa Williams, the first black Miss America, was forced to resign over explicit pictures published in Penthouse magazine. She told the 3,000 AKA members crammed into the ballroom, "This next song is very special. I was recording it in a music studio when I heard the news [about the title] over the radio."

After she brought the audience to their feet singing "Where Is the Love," Charles told the youngest AKA members, "Nothing comes easy. You have to stick it out." Then she added, "I had to wait 10 months to be Miss America."

"She's terrific," said Zora Callahan, a Wayne State University senior from Detroit. "You can tell she has intelligence. I'm glad to see the pageant isn't just interested in skin."

But Malline Morris, an AKA member from Indiana University, said the Miss America pageant "exploited women." She said she joined AKA because it provided her with "a network that could help me get jobs and friends," and said that she would not "have anything to do with the Miss America pageant."

Morris, a communications major, said that even though the AKA convention week is not over, she has already found a job. "A sister soror in Oklahoma is opening up a developmental communications firm, so I'll probably go there." Then the constant flash of cameras surrounding Charles caught Morris' eye. She looked up at the new Miss America, who, at 21, is her own age. "You know she's all right," said Morris. "And I feel sorry for Vanessa Williams, too. I guess people choose different routes to push ahead."

But in general, the issues of concern were larger.

"I've seen a lot of change in my time. But this year, it's at the fastest pace," said C. Elizabeth Johnson, who, even at 80, joined the rest of the convention in seeming to have no trouble at all keeping up.