Chicago Stadium, July 1944. 35,000 Democrats packed the sweltering convention hall, weaving signs, and screaming themselves horse. On the floor below, political bosses move through the crowd like sharks, cutting deals, making promises, twisting arms. Everyone in this building knows a secret they cannot speak out loud.

 Franklin Roosevelt is dying. The most powerful man in the world, the president who saved America from the Great Depression and now leads the fight against Nazi Germany and Imperial Japan will not survive another four years. Everyone can see it in his gaunt face, his trembling hands, the way he slumps in his wheelchair when he thinks nobody is watching.

 The next vice president will become president. That makes this the most important political decision in American history. and nobody has any idea who it should be. In a hotel room blocks away, Senator Harry Truman from Missouri sits with his wife Bess reading the newspaper. He wants nothing to do with this convention.

 For months, party leaders have whispered his name as a possible running mate for Roosevelt. Truman has told everyone who will listen that he is not interested. He does not want to be vice president. He knows what the job means. knows that Roosevelt is a dying man. Knows that whoever wins this nomination will inherit the weight of the entire world.

At 60 years old, Truman is happy where he is. He chairs the Senate Committee investigating waste in military spending during the war. The Truman Committee, as the press calls it, has saved taxpayers billions of dollars and made him one of the most respected men in Washington. Why would he give that up to become vice president? A job with no real power, no real purpose beyond waiting for the president to die.

 But the party bosses have other plans. In smoke-filled rooms across Chicago, men with expensive suits and expensive cigars are deciding the future of America. Robert Hanigan, chairman of the Democratic National Committee. Ed Flynn, political boss of the Bronx. Frank Walker, Postmaster General. Ed Paulie, party treasurer. These men control the Democratic Party like puppet masters pulling strings.

They have one goal. Stop Henry Wallace. Wallace is Roosevelt’s current vice president. A brilliant, eccentric man who speaks Russian, studies mysticism, and genuinely believes in progressive ideals that terrify conservative Democrats. Wallace wants to redistribute wealth, empower labor unions, and extend civil rights to black Americans.

 The party bosses despise him. They call him a communist sympathizer, a dreamer, dangerous. Some whisper that Wallace consults with psychics and believes in reincarnation. True or not, the rumors stick. The problem is that Wallace is popular with actual Democrats, the regular people who vote in elections. Polls show he has enough delegate support to win the nomination.

 The bosses need to find someone else, someone acceptable to everyone, someone who will not rock the boat. They consider James Burns, Roosevelt’s so-called assistant president, a former Supreme Court justice and the most powerful man in wartime Washington after Roosevelt himself. But Burns has problems.

 He was born Catholic but converted to Protestantism, which alienates Catholic voters. He comes from South Carolina and opposed anti-ynching laws which alienates black voters and northern liberals. The labor unions refused to support him. Burns is out. They consider William O. Douglas, another Supreme Court justice, young and dynamic.

 Roosevelt likes Douglas, but Douglas has no political experience beyond the bench. And party leaders worry he cannot deliver votes in the states they need to win. Douglas is out. They consider Alban Barkley, the Senate majority leader from Kentucky, respected and experienced. But Barkley is 70 years old, and nobody wants to nominate someone who might die before Roosevelt does. Barkley is out.

 That leaves Harry Truman, the junior senator from Missouri, who never went to college, who failed as a clothing store owner in Kansas City, and who rose to power with the help of Tom Pendergast, one of the most corrupt political bosses in American history. Truman is nobody’s first choice, but he is everyone’s second choice.

 And in politics, that is sometimes enough. Truman comes from Missouri, a border state that is neither fully southern nor fully northern, neither fully urban nor fully rural. He supported Roosevelt’s New Deal programs, but also opposed his controversial court packing plan, which makes him acceptable to both liberals and conservatives.

 Labor unions do not hate him. Catholics do not hate him. Southerners do not hate him. Northerners do not hate him. He is bland, safe, unexciting, perfect. The bosses go to Roosevelt and make their pitch. Dump Wallace. Choose Truman. Roosevelt does not care. He is focused on winning the war, on the upcoming Allied invasion of France, on the secret atomic bomb project that will change warfare forever.

 The vice presidency seems trivial compared to these worldshaking decisions. Roosevelt tells the bosses they can pick whoever they want as long as it is not Wallace. Then he confuses everything by writing notes to several people suggesting he would support them, including Wallace and Burns. Roosevelt, always the master manipulator, likes to keep his options open, likes to make everyone think they have his support until the last possible moment.

July 19th, the convention opens. Roosevelt is not even in Chicago. He is thousands of miles away in San Diego preparing to board a ship for Hawaii where he will meet with General Douglas MacArthur to plan the invasion of Japan. He will accept the nomination by radio from a Navy base. This is unprecedented. No major party nominee has ever accepted remotely before.

 But Roosevelt is tired, sick, and focused on the war. Domestic politics bore him now. On the convention floor, Henry Wallace supporters are loud and passionate. They flood the aisles chanting, “We want Wallace. We want Wallace.” On the first ballot, Wallace leads with 429 and a half votes. Truman gets 319 and a2.

 Wallace is short of the majority he needs, but he is close. Dangerously close. If there is a second ballot and Wallace gains momentum, he will win. The party bosses go to work. All night they move through the convention hall and hotel rooms talking to delegates, making promises, applying pressure. Postmaster General Frank Walker calls every chairman of every delegation personally.

 How many ambassadorships are promised? Nobody knows. How many judges ships? Nobody knows. How many government contracts and post office appointments and federal jobs? Nobody knows. But by morning, the tide has turned. Hanigan and Flynn find Truman in his hotel room and tell him Roosevelt wants him to run.

 Truman does not believe them. He has spoken to Roosevelt only twice since becoming a senator a decade ago. Why would Roosevelt suddenly want him as vice president? Hanigan picks up the phone and calls the White House, gets Roosevelt on the line, and puts it on speaker. Roosevelt’s voice crackles through the receiver loud enough for Truman to hear across the room.

 Bob, have you got that fellow lined up yet? Hanigan looks at Truman. He’s the contrarious goddamn mule from Missouri I ever saw. Roosevelt’s voice booms back, angry now. Will you tell him if he wants to break up the Democratic party in the middle of a war, that’s his responsibility. The line goes dead.

 Truman stares at the phone. Best looks at him. The weight of the moment settles over the room like a physical thing. Truman knows what is being asked of him. Roosevelt is dying. Everyone knows it, even if nobody will say it out loud. The next vice president will become president probably within a year or two, maybe sooner.

 That man will have to end the war, make peace with Stalin and Churchill, rebuild Europe, figure out what to do with this terrifying new atomic weapon. That man will shape the entire second half of the 20th century. Truman does not want to be that man. But Roosevelt just made it clear if Truman refuses, he will be blamed for splitting the party and potentially losing the election.

 At a time when American soldiers are dying on battlefields across the globe, when the fate of democracy hangs in the balance, Truman cannot be the selfish politician who puts his own comfort above his country. He nods. Well, if that’s the situation, I’ll have to say yes. But why the hell didn’t he tell me in the first place? July 21st, the second ballot.

 The bosses have done their work. Delegates who supported Wallace on the first ballot suddenly switch to Truman. The momentum is unstoppable. When the final count comes in, Truman wins decisively. 1,331 votes to Wallace’s 105. The crowd explodes in cheers, though many are confused. Who is Harry Truman? Only 2% of Americans pled earlier that summer wanted him as vice president.

 Most had never heard of him. Truman is driven to his aunt’s house before heading to Chicago. Aunt Ella is elderly and frail, and Truman wants to see her one more time. He sits in her living room and tells her about the nomination. She can see he is not happy. I’m going to the convention to defeat myself, Truman says. I don’t want to be vice president.

But it is too late. The machine has made its decision. The bosses have spoken. Roosevelt has given his approval, however reluctantly. And Harry Truman, the failed habeddasher from Independence, Missouri, the product of the Pendergast machine, the man nobody wanted, is going to be the next vice president of the United States.

November 1944, Roosevelt and Truman win the election easily. Roosevelt gets 432 electoral votes to Republican Thomas Dwiey’s 99. The American people in the middle of the biggest war in human history are not interested in changing leadership. Roosevelt is sworn in for his fourth term on January 20th, 1945. Truman is sworn in as vice president the same day.

 He calls his mother in Missouri. Now you behave yourself, she tells him. Truman’s time as vice president is brief and frustrating. Roosevelt does not include him in any important decisions. Truman is not told about the Manhattan project, the secret program to build an atomic bomb. He’s not briefed on military strategy.

 He’s not consulted on diplomatic negotiations with Stalin and Churchill. Roosevelt treats him the way presidents have always treated vice presidents, as an irrelevant figurehead whose only job is to preside over the Senate. And wait, Truman meets privately with Roosevelt only twice during his 82 days as vice president.

 At their last meeting in late March 1945, Truman is shocked by Roosevelt’s appearance. The president looks like a skeleton. His hands shake so badly he cannot light his own cigarette. His skin is gray. When he speaks, he slurs his words. Truman leaves that meeting convinced Roosevelt will not live much longer. April 12th, 1945, a Thursday afternoon.

The Senate has just adjourned for the day. Truman heads to House Speaker Sam Rabburn’s office in the capital for a drink, as he often does. Rayburn’s office is a comfortable place where a few friends gather to relax and talk about nothing important. Truman pours himself a bourbon. The phone rings. Rayurn answers, listens, then hands the receiver to Truman.

 It’s the White House. They want you immediately. Truman assumes he’s being summoned for some routine meeting. He drives to the White House, parks, and walks through the front entrance. He’s met by Eleanor Roosevelt, the first lady. Her face tells him everything before she says a word. Harry, the president, is dead. Truman feels the world tilt.

 He cannot speak. Finally, he manages to ask, “Is there anything I can do for you?” Eleanor Roosevelt looks at him with something like pity. Is there anything we can do for you? For you are the one in trouble now. Within two hours, Chief Justice Harlon Stone administers the oath of office in the cabinet room. Truman’s right hand is raised, his left hand on a Bible.

 Bess stands beside him, her face pale. Cabinet members and staffers crowd into the small room. At 7:09 p.m., Harry Truman becomes the 33rd president of the United States. He is 60 years old. He never graduated from college. He failed in business. He owes his entire political career to a corrupt machine boss who went to federal prison.

He has been vice president for exactly 82 days. He knows nothing about the atomic bomb, nothing about Roosevelt’s secret agreements with Stalin, nothing about the military plans to invade Japan. And now he is the most powerful man in the world in charge of a nation still fighting the biggest war in human history.

 The next morning, Truman meets with reporters. Someone asks how he feels. Truman’s answer is simple and honest. I felt like the moon, the stars, and all the planets had fallen on me. 3 weeks later, on May 7th, Germany surrenders. The war in Europe is over. Truman dedicates the victory to Roosevelt, the man who led the fight but did not live to see it end.

 On July 25th, Truman learns the details of the Manhattan project. Secretary of War Henry Stimson briefs him on the successful test of the atomic bomb in New Mexico. Stimson hands Truman a note that reads, “We have discovered the most terrible bomb in the history of the world.” Truman makes the decision Roosevelt never had to make.

 He authorizes the use of atomic bombs on Hiroshima. on August 6th and Nagasaki on August 9th. Japan surrenders on August 15th. The war is over. 50 million people are dead. And Harry Truman, the man nobody wanted, the compromise candidate chosen by party bosses in a smoke-filled room, has ended the most devastating conflict in human history.

 Looking back, the Democratic Convention of 1944 seems almost absurdly casual about one of the most important decisions in American history. A handful of political bosses chose the man who would lead America into the atomic age, who would face down Stalin and begin the Cold War, who would rebuild Europe with the Marshall Plan, who would integrate the military and advance civil rights.

 They chose him not because he was the best man for the job, not because he was particularly qualified, but because he was acceptable to everyone and threatening to no one. And yet somehow it worked. Harry Truman, thrust into the presidency with no preparation, no briefing, no support from the man who preceded him, rose to the occasion.

 He made decisions that shaped the modern world. He proved that leadership can emerge from unexpected places, that ordinary men can do extraordinary things when circumstances demand it. But on that July day in Chicago in 1944, none of that was clear. All anyone knew was that Franklin Roosevelt was dying, Henry Wallace had to be stopped, and Harry Truman was the safest choice.