CHICAGO, JUNE 20 -- Until this week, the U.S. Conference of Mayors had not met in Chicago since 1968, the summer of the "Siege of Chicago" and its infamous, violence-wracked Democratic National Convention, when Mayor Richard J. Daley was at the peak of his power.

It has taken this long for Chicago to outlive the bitter memories of that time and of the televised scenes of police cracking the heads of anti-war demonstrators on the tear-gassed streets of the place its citizens proudly call "the city that works."

But the nation's big city mayors were finally back in Chicago this week, hosted by another Mayor Daley, Richard M., who after 14 months in the office long occupied by his father has emerged as a surprisingly agile political figure in his own right.

Daley, who like his father is decidedly pro-business, marshaled the kind of show for his fellow mayors that would have made his father proud. One night the mayors took over the Board of Trade for a banquet; the next night they visited a Monet exhibition at the Art Institute. There was a "say no to drugs" parade, an evening at the Museum of Science and Industry, a boat trip on Lake Michigan and even a visit to Comiskey Park, in Daley's home neighborhood, to see the surprisingly hot Chicago White Sox lose to the world champion Oakland Athletics, 5-2.

It was the most extravagant weeklong show of power and glitz that the mayors conference has seen in decades, the kind of spectacle few other American cities could match. The entertainment tab for the 250 mayors and 1,800 aides came to $1 million.

It was paid by Daley's friends in corporate Chicago. "People have been very impressed. It's been on a scale second to none," said Mike Brown, director of public affairs for the Conference of Mayors.

For Daley, who as a boy attended national meetings of the mayors' organization with his father, the week was another step in establishing an identity as a national political figure. Richard J. Daley, the last of the big city political bosses, was a larger than life figure -- tough, combative and domineering. His nicknames projected that image: "duh Mare," "Hizzoner," "Boss" "the Man on Five" (the mayor's office is on the fifth floor of city hall) and "Himself."

Richard M. Daley, elected to complete the final two years of the second term of the late mayor Harold Washington, suffered by comparison. He was often underestimated as dull and unimaginative, a child of privilege, living off his father's name and reputation. Even after two successful terms as Cook County state's attorney, news profiles routinely described him as "the son of the Boss," and invariably noted that it took him three tries to pass the bar exam.

But after only 14 months in office, nobody talks about "son of the Boss" or doubts the new mayor's adeptness at tackling complex issues and remaining a step ahead of political enemies.

With his opposition splintered, Daley is extremely popular among white voters, the business community and the Chicago media, which has treated his administration with kid gloves. A poll by the Southtown Economist newspaper and WBBM-TV in March showed Daley with a 71 percent approval rating, making him a formidable favorite to win a full, four-year term in 1991. Fellow mayors were impressed with the Daley they saw this week. "He is very aggressive and focused and has strong opinions about cities," Louisville Mayor Jerry Abramson said.

Daley also showed a combative streak today, leaping to the defense of his father's longtime ally, Rep. Dan Rostenkowski (D-Ill.), chairman of House Ways and Means Committee. On Tuesday, Rostenkowski angered many Democratic mayors by telling them, "If you were hoping for a peace dividend, you will be disappointed. The peace dividend has already been invested in the savings and loan bailout."

The mayors complained that Rostenkowski and other congressional Democrats should be fighting for their urban constituents rather than going along with the Bush administration on the bailout.

A red-faced Daley stepped in when Boston Mayor Raymond Flynn made these complaints public during a news conference today that was called to endorse a new domestic lobbying agenda seeking major increases in federal funding for housing, education, anti-drug and other urban programs.

"Chairman Rostenkowski told the truth. If some people don't like it, so be it," an angry Daley said.

The last time the mayors met in Chicago was June 1968, the week after Robert F. Kennedy was assassinated in Los Angeles. Two months earlier, Dr. Martin Luther King Jr. had been gunned down in Memphis, setting off a wave of riots in Chicago and other cities.

J. Thomas Cochran, executive director of the Conference of Mayors, recalls a somber, dispirited atmosphere at the 1968 meeting, and that many of the Democratic mayors who attended their national convention here two months later left disgusted with the city. But Cochran said the conference made no deliberate effort to avoid Chicago for the next two decades.

Daley, however, is acutely aware of the city's image. "We know we have a wonderful city, but that it's largely a secret," press secretary Avis LaVelle said. "We had some mayors tell us they dreaded coming to Chicago."