On the eve of one of the most momentous days in our nation's history, Oprah is in Washington, D.C., at the Kennedy Center to celebrate the inauguration of President-elect Barack Obama. On this day 46 years ago, Martin Luther King Jr. shared his dream with the world on the steps of the Lincoln Memorial. "Tomorrow, Barack Obama will fulfill that dream when he becomes the 44th president of the United States," Oprah says.

Oprah isn't alone in celebrating—among the millions of spectators expected at Inauguration Day 2009 are a few friends who have stopped by to express how they feel on this day.
Ashton Kutcher and Demi Moore

Ashton Kutcher and Demi Moore say Washington is buzzing with excitement. "I'm shaking," Demi says. "I just feel so much gratitude for my children to be experiencing this," she says.

Like Oprah, Ashton says he became a supporter of President-elect Obama after his 2004 speech at the Democratic National Convention. Ashton says he and Demi were able to attend a gathering with the then-Senator Obama, who had yet to declare his run for presidency. "He said, 'Making a decision like that is going to affect my whole family. It's going to affect my wife. It's going to affect me. And I have to take into consideration how it's going to affect them before I can make that decision for myself.' And I thought, 'If we have somebody who can run our country and see the world in that way—where he's thinking about their best interests before our own, about family, about the world—that's a world I want to live in,'" Ashton says.
Demi Moore

Demi says this is the first time she has publicly endorsed a candidate, and she didn't want to do it halfway. Although public speaking is one of her fears, she says she drove to Iowa to speak at colleges in support of Obama. "I felt like if I didn't go and participate to do something to put out my best effort, even at the sake of humiliating myself, then I wouldn't feel that I had done enough."
Ashton Kutcher

As the world waits for Obama to be sworn in as president, Ashton and Demi are hoping to initiate change now. The couple is pledging to answer Obama's call to service with a special project to ignite the passion for positive change with their fellow citizens.

For their new Web video "I Pledge," Ashton and Demi asked their celebrity friends and colleagues to state their pledge for change as a way to inspire others and hold them accountable for how they're willing to be of service. "Because ultimately, if we really are inspired, then we will see the change that we want," Ashton says.

From Cameron Diaz to Sean "Diddy" Combs to Dakota Fanning to Eva Mendez, watch what celebrities are pledging to change in their livesWatch
Luke Russert

NBC youth correspondent Luke Russert, son of the late news anchor Tim Russert, says his ideas of politics stem from his family. "Anything really is possible," he says. "I mean, what a country. If there's anyone out there who still disputes that America's the land of utmost opportunity, after this election, they surely are wrong."

Newark Mayor Cory Booker on the impact of the 2008 election Watch
Anderson Cooper

The presidential inauguration is a uniquely American ceremony that began over 200 years ago. "Every president since George Washington has given an inaugural speech to express his vision for the country, and they often contain some of the most powerful words, which we remember even to this day," CNN's Anderson Cooper says. "After the swearing-in ceremony ... it is Barack Obama's United States of America, and it is from there that a new chapter in the life of our country begins."
Vice President-elect Joe Biden and his wife, Jill

Before President-elect Obama is sworn into office, another man will take his oath before him. Vice President-elect Joe Biden, who has served his country as a senator for more than 30 years, will take his own place in history. In a surprise visit to The Oprah Winfrey Show, Vice President-elect Biden and his wife, Jill, are sharing the experience.

Vice President-elect Biden wasn't always going to be President-elect Obama's right-hand man. "Look, I started off trying to get the nomination for president," he says. "Barack Obama and I debated each other eight, nine times." However, when he was asked to be Obama's number two, he says he knew what he was getting into. "I asked what he expected of me, and he said he wanted to have a confidant and someone who wouldn't be a yes man," he says.
Jill Biden

Although her husband begins his new job tomorrow, Jill says she plans to keep her career goals. "I'm still going to be teaching, yes," she says. "I've taught for 27 years. I've been an educator. I love my students. I say they're my heroes, and I'm still going to teach."
Vice President-elect Joe Biden

Jill says her husband's decision to accept the vice presidential nod came after a family discussion.

"Because I think Joe had the choice to be secretary of state or vice president. ... So I said, 'Joe, if you're secretary of state, you'll be away, we'll never see you, you know, I'll see you at a state dinner once in a while,'" Jill says. "But I said if you're vice president, the entire family—because they worked so hard for the election—can be involved. They can come to our home. They can go to events. They can be with us all the time. And that's what's important to us."

After the show, Vice President-elect Biden's spokeswoman Elizabeth Alexander denied Jill's account in a statement e-mailed to reporters.

"To be clear, President-elect Obama offered Vice President-elect Biden one job only—to be his running mate," the statement said. "And the vice president-elect was thrilled to accept the offer."
Usher and MTV's Kim Stoltz

Inspired by President-elect Obama's call to service, Grammy award-winning artist Usher and MTV's Kim Stoltz are volunteering at Simon Elementary School in Washington, D.C. The school serves 300 kids, but Kim says the dropout rate is 50 percent. Along with 200 volunteers from MTV, Target and ServiceNation, Usher and Kim and hoping to make a difference by renovating the school's library.

With a new president set to take office tomorrow, Usher says it's not only a new day, but a new generation. "Generation S is a generation of service-minded youth leaders," he says. "Actually being able to take advantage and take control of your community and make a difference—it's something that you can do, no matter where you are."
Will.i.am, David Foster, Faith Hill, Mary J. Blige, Seal and Bono perform America's Song.

Legendary music producer David Foster and Will.i.am, the man behind "It's a New Day" and "Yes We Can," have joined forces to create a song to capture this moment in history. Along with Faith Hill, Seal, Bono and Mary J. Blige, the artists premiere their new anthem, "America's Song."

Watch videos of "America's Song"

Follow Lisa Ling and Oprah.com producers as they visit Washington, D.C., landmarks and witness history