Americans are marking Presidents’ Day with old wars smoldering and new ones threatening to erupt. The Constitution tasks President Trump with leading America through these fires and, by following predecessors forged by war, he can find the path to a lasting peace.

The federal holiday on February 17 is Washington’s Birthday. Americans picture him as an old man with a powdered wig and false teeth. Little remembered is young Washington, the headstrong British soldier whose aggressiveness sparked the French and Indian War.

Washington learned from his mistakes. He was a different man — the indispensable man — when called to lead the Continental Army. He released his anger at moments of his choosing not in fits of self-defeating pique.

In his funeral oration, Major General Henry “Light Horse Harry” Lee documented Washington’s accomplishments. He was, Lee said, “First in war, first in peace, and first in the hearts of his countrymen.” It was an example that Washington laid down with purpose for his successors.

President Jackson dissented from many policies of Washington’s Federalists but had great respect for him. When Jackson delivered the American army’s upset victory over the British in the War of 1812, at the Battle of New Orleans, it was with a ragtag group much like the one Washington led at Valley Forge.

Having participated in over 100 duels, Jackson used his reputation for violence to his advantage. He’d sometimes rage at a visiting member of Congress, only to be found laughing about his performance afterwards.

Whigs feared that “King Andrew” would plunge the nation into war, but his two terms were peaceful. Rather than resort to fighting, he offered Mexico’s envoy, General Santa Ana, $6 million for their territory of Texas and accepted it when he declined.

“No man,” a Jackson supporter, Francis Blair, wrote of the meeting, “ever gave another a better lesson of patriotism and public virtue … not only in words, but in the example … of simplicity, probity, and power” that Santa Anna “saw before him.”

President Lincoln held up Washington’s example throughout the Civil War. Allowing that Washington had flaws, Lincoln nevertheless encouraged believing that he “was spotless,” because “it makes human nature better to believe that one human being was perfect.”

Lincoln, who extended a hand of peace to the Confederates even before their defeat, said Washington’s mythos gave Americans something to strive for by showing “that human perfection is possible.” In every great crisis since, both men have been held up as ideals.

After United States Ship Maine exploded in Havana Harbor, a tearful President McKinley told a friend, “Congress is trying to drive us into war with Spain.” When Madrid chose a fight, McKinley applied what he’d learned in the Civil War to ensure a swift victory and just peace. A portrait of Spanish envoys signing an end to the conflict now hangs in the White House Treaty Room.

Like Jackson, McKinley’s successor, President Theodore Roosevelt — a hero of the war in Cuba — employed a version of President Nixon’s Madman Theory, a president so volatile that enemies dared not challenge him. Roosevelt’s years were also marked with peace, and Nixon ended the war in Vietnam.

Marking Washington’s 250th birthday in 1982, President Reagan touted him as “a giant for freedom.” After President Eisenhower, Supreme Allied Commander in World War II, kept the Cold War from going hot, Reagan ended it in triumph and did so without triumphalism.

Reagan, Prime Minister Thatcher said in her eulogy, beat the USSR “not only without firing a shot, but also by inviting enemies out of their fortress and turning them into friends.” This sentiment echoed Lincoln’s rhetorical question to those who sought punishment for the South.

“Do I not destroy my enemies,” Lincoln asked, “when I make them my friends?” President Grant carried this same spirit. He offered generous terms to General Lee at his surrender and declared the words chiseled in stone over his mausoleum: “Let us have peace.”

This Presidents’ Day, Mr. Trump is preparing to meet with President Putin to discuss the war in Ukraine, inviting Iran to negotiate, and confronting foes from Hamas to Communist China. Those who preceded him stand ready to guide his steps, warning about the cost of war and the wisdom of making peace.