President Donald Trump

President Donald Trump

Donald John Trump was inaugurated as the 45th president of the United States on Friday, ushering in a new and more unpredictable era in which he has vowed to shatter the established order and restore American greatness.

From the West Front of the Capitol, overlooking a crowd of admirers gathered as rain threatened on an overcast day, Mr. Trump used his Inaugural Address to promise that he will use the next four years to rebuild the nation’s economy, reassert control over its borders and regain respect for the United States around the world.

“We the citizens of America are now joined in a great, national effort to rebuild our country and restore its promise for all of our people,” he said. “Together we will determine the course of America and the world for many, many years to come. We will face challenges. We will confront hardships. But we will get the job done.”

He said the inauguration represented not just the peaceful transfer of power from one part to another. “We are transferring power from Washington, D.C. and giving it back to you the people,” he said.

For too long,” he added, “a small group in our nation’s capital has reaped the rewards of government while the people have born the cost. Washington flourished but the people did not share in its wealth. Politicians prospered but the jobs left and the factories closed. The establishment protected itself but not the citizens of our country. Their victories have not been your victories. Their triumphs have not been your triumphs.”

He vowed to reverse that trend and make America first. “The forgotten men and women of our country will be forgotten no longer.”

Mr. Trump, wearing a dark suit with red tie and accompanied by Melania Trump in a powder-blue suit, intends to waste little time after taking the 35-word oath that was administered by Chief Justice John G. Roberts Jr. to start unraveling the policies of his departing predecessor, President Obama. Within hours of taking office, the new president could begin signing executive orders freezing regulations put in place in the last weeks of Mr. Obama’s tenure and reversing policies on health care, immigration and other areas.

His son, Donald Trump Jr., said the new president was coming to grips with the gravity of his new position, even if it did not necessarily seem so in public. “He’s been humbled by the whole process,” he said on MSNBC. “And you know, whether he shows that outwardly or not is, you know, is one thing.”