At the new memorial to Martin Luther King Jr., hundreds gathered to pay homage to the man who delivered his “I Have a Dream” speech in 1963 on the Mall, 45 years before Obama’s election. Martin Luther King III called upon the crowd to remember his father, the man whose likeness is now etched in stone.

“We are a better nation than the behavior we’re exhibiting,’’ he said. “We must continue [my father’s] mission.”

Said Dorian Stubblefield, a 14-year-old Boy Scout from Silver Spring, Md: “We’re on our way to reaching our dream, but this is just another step . . . We’re not there yet.”

The weather forecast for Monday during the inauguration is for mostly cloudy skies, with a 30 percent chance of rain in the afternoon and a high of 44 degrees.

Obama’s inauguration speech is expected to focus on broad themes that will urge Americans to be more active in politics, as well as make a new call for bipartisanship.

“He is going to say that our political system does not require us to resolve all of our differences or settle all of our disputes but it is absolutely imperative that our leaders try and seek common ground when it can and should exist,” David Plouffe, a senior adviser, said Sunday on ABC’s “This Week.” “That’s a very important part of the speech.”

Obama’s State of the Union address, which will come in about three weeks, will be more focused on the specific policy proposals expected to guide his next term, including immigration, gun control, and climate change. The next few months, though, will be largely guided by financial issues such as raising the debt ceiling and cutting the growth of the budget.

After his speech and swearing-in ceremony, Obama will join members of Congress for lunch.

After the luncheon, Obama will lead a parade down Pennsylvania Avenue, from the Capitol to the White House. The parade includes three groups from Massachusetts, more than any other state: the Boston College marching band, the Boston Crusaders Drum and Bugle Corps, and the 54th Massachusetts Volunteer Regiment.