President Elect Joseph R. Biden Jr. spoke to the nation Saturday evening for about 20 minutes at the Chase Center in Wilmington, Delaware, and summarized what he thought was his mandate from the voters in the election. The crowd, many of whom stood outside their parked cars and pickup trucks, were jubilant.

Kamala Harris, Vice President Elect, introduced Mr. Biden “as a president for all Americans” who would strive to unite the nation.

A Call to Unity

“I pledge to be a President who seeks not to divide, but to unify, who doesn’t see red and blue states, but a United States, and who will work with all my heart to win the confidence of the whole people,” said Mr. Biden.

“And I will be honored to be serving with a fantastic Vice President — Kamala Harris — who will make history as the first woman, first Black woman, first woman of South Asian descent, and first daughter of immigrants ever elected to national office in this country.

“It’s long overdue, and we’re reminded tonight of all those who fought so hard for so many years to make this happen. But once again, America has bent the arc of the moral universe towards justice.”

Mr. Biden reached out to people who voted for Mr. Trump, saying, “Let’s give each other a chance. It’s time to put away the harsh rhetoric, to lower the temperature, to see each other again, to listen to each other again. To make progress, we must stop treating our opponents as our enemy. We are not enemies. We are Americans.”

The Mandate

“I believe it is this: Americans have called on us to marshal the forces of decency and the forces of fairness. To marshal the forces of science and the forces of hope in the great battles of our time:

        The battle to control the virus.

        The battle to build prosperity.

        The battle to secure your family’s health care.

        The battle to achieve racial justice and root out systemic racism in this country.

        The battle to save the climate.

        The battle to restore decency, defend democracy, and give everybody in this country a fair shot.”

“Our work begins with getting Covid under control.

“We cannot repair the economy, restore our vitality, or relish life’s most precious moments — hugging a grandchild, birthdays, weddings, graduations, all the moments that matter most to us — until we get this virus under control.

“On Monday, I will name a group of leading scientists and experts as transition advisers to help take the Biden-Harris Covid plan and convert it into an action blueprint that starts on Jan. 20, 2021.

“That plan will be built on a bedrock of science. It will be constructed out of compassion, empathy, and concern.

“I will spare no effort — or commitment — to turn this pandemic around.”

A Mandate to Cooperate

“I ran as a proud Democrat. I will now be an American president. I will work as hard for those who didn’t vote for me — as those who did.

“Let this grim era of demonization in America begin to end — here and now.

“The refusal of Democrats and Republicans to cooperate with one another is not due to some mysterious force beyond our control.

“It’s a decision. It’s a choice we make.

“And if we can decide not to cooperate, then we can decide to cooperate. And I believe that this is part of the mandate from the American people. They want us to cooperate.

“That’s the choice I’ll make. And I call on the Congress — Democrats and Republicans alike — to make that choice with me.”

The Promise of Opportunity

“We must make the promise of the country real for everybody — no matter their race, their ethnicity, their faith, their identity, or their disability.

“We have the opportunity to defeat despair and to build a nation of prosperity and purpose.

“We can do it. I know we can.

“I’ve long talked about the battle for the soul of America.

“We must restore the soul of America.

“Our nation is shaped by the constant battle between our better angels and our darkest impulses.

“It is time for our better angels to prevail.”

Mr. Biden said we are looking ahead “to an America that’s freer and more just, … to an America that creates jobs with dignity and respect, …to an America that cures disease — like cancer and Alzheimers, … to an America that never leaves anyone behind, to an America that never gives up, never gives in.

“Let us be the nation that we know we can be: a nation united, a nation strengthened, a nation healed, the  United States of America.”