Muriel E. Bowser was sworn in Friday as the District’s seventh mayor, pledging to bring “grand expectations” to a city that has struggled to move past an ethical morass.

Bowser, 42, the second woman and the second-youngest person to lead the nation’s capital, acknowledged a series of intractable problems and said she would use “creativity, risk-taking and innovation” to solve them.

“We’ve come a long way in this city together,” she said in her inaugural address. “But the challenges that remain are among the toughest.”

“I’m ready to get to work,” she concluded.

Bowser (D) and the other public officials sworn in Friday — seven D.C. Council members and, for the first time, an elected attorney general — struck similar notes of optimism and collaboration.

Mayor Muriel E. Bowser (D) was sworn in along with seven members of the D.C. council on Friday, saying she intends to respect the branches of government and be a "collaborative mayor." (DCN)

Most identified similar problems that demanded their attention: housing prices spiraling out of reach, a troubling spate of family homelessness, persistent gaps in educational and economic opportunities, an erosion of public trust in government and the District’s continued subservience to Congress, a body in which residents have no voting representative.

But the speeches offered more in the way of recognition of those problems than solutions. Beyond pledging to create an “amped-up” effort to coordinate with federal and regional officials, Bowser did not use the opportunity, in addressing more than 1,000 people gathered at the Walter E. Washington Convention Center, to present any significant new initiatives.

And there were signs that old tensions may persist — glimpses of political fault lines that could widen as officials settle into the John A. Wilson Building.

Before the new mayor pledged to “confront our challenges head-on,” D.C. Council Chairman Phil Mendelson (D) warned against a return to “the days of destruction and confrontation” — an unmistakable reference to the bitter intra-governmental divides that were seen during the administration of Mayor Adrian M. Fenty, Bowser’s political mentor.

“Results are important, but the way we govern is also important,” Mendelson told the crowd, which included Fenty. “Good government comes from an attitude that people are important, that accountability means transparency, that collaboration is essential and that usually the right result is the one that had broad support.”

Bowser took the oath of office flanked by her father, Joseph, a retired facilities manager for D.C. Public Schools, and her mother, Joan, retired from nursing. Eric T. Washington, chief judge of the D.C. Court of Appeals, delivered the oath.

Her parents sat front and center amid a who’s who of regional officials, including former D.C. mayors Fenty and Anthony A. Williams, Philadelphia Mayor Michael A. Nutter, Baltimore Mayor Stephanie Rawlings-Blake, Montgomery County Executive Isiah Leggett, Prince George’s County Executive Rushern L. Baker III, Alexandria Mayor William D. Euille, Maryland Lt. Gov. Anthony G. Brown and Prince George’s County State’s Attorney Angela Alsobrooks.

While attending D.C. Mayor Muriel Bowser's (D) inauguration ceremony on Friday, former mayor Adrian Fenty said he believes Bowser has the potential to not only be one of the greatest mayors of D.C. but in the country. (Hamil Harris)

Nutter, a past president of the U.S. Conference of Mayors, said he had delivered some advice to his soon-to-be colleague: “She can’t take any of it personally. People have to say what they’re going to say. Stay focused — that’s the important thing.”

Also present for the inauguration was Vincent C. Gray (D), the one-term mayor Bowser unseated in the Democratic primary amid a criminal investigation into his 2010 campaign that is still unfinished. Gray’s bid for reelection was soundly derailed after prosecutors charged a businessman, Jeffrey E. Thompson, with secretly funding his prior campaign. In a plea deal, Thompson alleged that Gray knew of the illegal arrangement. Gray has not been charged.

Gray later handed Bowser the city seal, whispering in her ear as he did so. “I told her this was a great job and she should do everything she can to enjoy it,” Gray said afterward.

Bowser later thanked Gray for his “leadership” and “successes,” a gesture of reconciliation after the hard-fought primary. The acknowledgment brought many in the crowd to their feet.

Her speech otherwise blended optimism and realism for a city she called “both rich with prosperity and rife with inequality.”

Bowser acknowledged a budget gap exceeding $200 million, which could prove to be a hindrance to her agenda and a source of political tension. But she still pledged to make the city “greener, healthier, safer and more fiscally stable than we find it today.”

She laid out a first-term blueprint that ranged from the minutia of city government — clearing snow, collecting garbage, synchronizing traffic lights and paving streets — to ambitions on a global scale.

Among her grand expectations, she said, is “winning the Olympics for Washington, D.C., in 2024.”

Bowser was part of a small Washington delegation that made a presentation last month to the U.S. Olympic Committee, which is expected to select one city in coming weeks to put forth as the official American bid. Should the District be chosen, it would kick off nearly two years of planning ahead of the International Olympic Committee’s final selection — and then perhaps eight more years of fierce preparations.

Other speakers — including three new council members and four who won reelection — spoke about less-speculative issues.

“We lock up too many people. We train folks for jobs but offer too little help in placement. We offer a form of shelter to the homeless, but everybody knows we need more affordable housing,” said Mary M. Cheh (D-Ward 3), kicking off her third term. “These are the kinds of things that will need our immediate attention. Today we have great hopes, and . . . we have the energy, the vitality and the focus to move ahead.”

Among the newcomers, Charles Allen (D-Ward 6), a former chief of staff to departing member Tommy Wells, called for a new commitment to ethics in government.

“A focus on integrity is not just a campaign-season issue,” he said. “It must be built into the character of our elected officials and demanded by our residents. . . . I believe this council is ready to restore that trust and that its best days are still ahead.”

Elissa Silverman (I-At Large), a former newspaper reporter, said she would work to ensure that a story like the disappearance of 8-year-old Relisha Rudd from a city homeless shelter “is never, ever written again.”

And Brianne K. Nadeau (D-Ward 1) declared an “affordable housing crisis” and lamented laws that “unfairly lock up African American boys.” She called for the community to become engaged in fixing those problems.

First to be sworn in Friday was Karl A. Racine, the District’s first elected attorney general.

The former public defender, White House lawyer and law firm managing partner beat four other candidates after a long period of uncertainty about whether the election would ever take place.

The son of Haitian immigrants, Racine pledged to “use the law as a tool to serve the residents of this great city” and added that he would be “fierce and unyielding in defending the will of the people.” That, he said, included defending the city’s recent marijuana legalization referendum against congressional attempts to overturn it.

But Racine also staked his place in the District government firmament as a potential check and balance on the mayor and council. If those in government act against the law, he said, “I must and I will uphold the law.”

Friday night, an even larger crowd of supporters packed the convention center for Bowser’s inaugural ball.

Soaring red stripes and a line of stars adorned a wall like wings in a modern interpretation of the D.C. flag. The main stage was set for Prince protege Sheila E., whose career as a pop star crested when Bowser was a 12-year-old middle school student in 1984.

Before Bowser was expected on stage near 10 p.m., band members of the late go-go legend Chuck Brown took the microphone and began chanting Bowser’s campaign slogan: “All eight wards!” The crowd answered with a roar.

Bowser spent much of the first three hours of the ball a floor below the dance area in a VIP lounge with about 200 invited guests, including members of her new cabinet and major donors.

Anita D. Bonds (D-At Large), who began her first full term Friday after filling a vacant seat for two years, said Friday’s festivities demonstrated that the coming years of city government “started off right.”

“It’s a lovefest, and I think if we work hard, the love will continue,” she said. “There will be some ups and downs, but that’s what happens in a love affair.”

Hamil R. Harris, Steve Hendrix and Arelis Hernández contributed to this report.