Truman recognized the State of Israel on May 14, 1948, eleven minutes after it declared itself a nation. Of his decision to recognize the Israeli state, Truman wrote in his memoirs: "Hitler had been murdering Jews right and left. I saw it, and I dream about it even to this day. The Jews needed some place where they could go. It is my attitude that the American government couldn't stand idly by while the victims [of] Hitler's madness are not allowed to build new lives."

Presidents have been getting code names ever since Harry Truman, who was called "General." Previously, code names had only been assigned to first ladies Edith Wilson ("Grandma") and Eleanor Roosevelt ("Rover").

During the 1948 presidential campaign, Truman delivered a speech attacking Republicans in Bremerton, Washington. During the speech, a supporter yelled, "Give 'em Hell, Harry!" Truman replied, "I don't give them Hell. I just tell the truth about them, and they think it's Hell." Subsequently, "Give 'em Hell, Harry!" became a lifetime slogan for Truman supporters.

In one of the greatest election upsets in American history, Truman defeated Republican Governor Thomas E. Dewey. The defining image of the campaign came after Election Day, when an ecstatic Truman held aloft the erroneous front page of the Chicago Tribune with a huge headline proclaiming "Dewey Defeats Truman." Truman's surprise victory was the fifth consecutive presidential win for the Democratic Party, the longest winning streak for either party since the 1880 election.

The Truman Doctrine, first expressed in a speech to Congress on March 12, 1947, established that the United States would provide political, military and economic assistance to all democratic nations under threat from external or internal authoritarian forces. The Truman Doctrine became the foundation of American foreign policy, and led, in 1949, to the formation of NATO. Historians often consider Truman's speech as the beginning of the Cold War.

On June 25, 1950, the North Korean army under Kim Il-sung invaded South Korea, starting the Korean War. Truman called for a naval blockade of Korea, only to learn that due to budget cutbacks, the U.S. Navy could not enforce such a measure. Truman promptly urged the United Nations to intervene, and it did, authorizing troops under the UN flag led by U.S. General Douglas MacArthur. Truman decided he did not need formal authorization from Congress, believing that most legislators supported his position. This would come back to haunt him when the costly conflict was dubbed "Mr. Truman's War" by legislators.

Truman vetoed a total of 250 bills--180 regular vetoes and 70 pocket vetoes. Congress overrode 12 of Truman's vetoes, including his vetoes of the Taft-Hartley Act, which weakened labor unions, and the McCarran Internal Security Act, which established the Subversive Activities Control Board to investigate suspected communist and/or fascist sympathizers.

Truman's famous motto, "The buck stops here", was emblazoned on a thirteen-inch sign that sat on his Oval Office desk.

In 1965, President Lyndon B. Johnson signed the Medicare bill at the Harry S. Truman Presidential Library and Museum and gave the first two Medicare cards to Truman and his wife Bess to honor the former president's fight for government health care while in office.

On December 5, 1972, Truman was admitted to Kansas City's Research Hospital and Medical Center with pneumonia. He developed multiple organ failure, fell into a coma, and died at 7:50 a.m. on December 26, at the age of 88.