Why was Harry Truman chosen to be Vice President in 1944?

Question

In 1944, FDR was running for his fourth and final election. He was starting to age rapidly, he would be dead in just 82 days from being sworn in to his fourth term. Henry Wallace had been FDR's VP from 1941-1945. At the 1944 Democratic Convention FDR would be forced in the name of party unity to leave Wallace off the ticket. Wallace had recently become a Democrat and some felt too recently. Wallace was more liberal than FDR and that also was a strike against him. Finally Wallace was a Theosophist, which lead many to think he wasn't christian and was just too whacky to become President.

Question: Why was the Junior Senator from the backwater of Missouri chosen as Henry Wallace's replacement? What had Harry Truman a former county Judge who had never graduated from college, achieved which made him favored to ascend to the Vice Presidents spot? What had earned Truman such great respect that he was the consensus candidate for this important job to a sickly President in a time of war?

Answer 1

There is an extensive Wikipedia article on the details of the selection process. Truman had become a national figure through his chairmanship of the Senate Special Committee to Investigate the National Defense Program which had saved $10-15 billion of the cost of WWII, by preventing inefficiency, waste and profiteering, at a cost of $360,000. It was clear that Truman could get things done, and with Roosevelt ailing, that was a valuable quality in a Vice-President.

Answer 2

Truman balanced Roosevelt's ticket in several important ways. First, he was a Senator (Roosevelt had been Governor of New York). He came from a poor background; Roosevelt was a rich man trying to convince poor people that he was acting in their interests, against fellow members of his "class." Truman was someone who had "worked with his hands," at a time when most voters did so, and had not been to college. Even so, Truman was "right" of (less radical than) FDR in his own party, not to mention Henry Wallace.

The geographical factor was not unimportant. Missouri, besides being a decent-sized state, was close to the geographical and cultural center of the country. It was a good answer to Will it play in Peoria? Basically, it was on the edge of both the Midwest and the South; having been the "border state" nearest to Kansas before the Civil War. Roosevelt was rightfully confident about his ability to hold the key northeastern states of New York, Pennsylvania and New Jersey, but needed help in the Midwest; Ohio, Michigan, Illinois, Wisconsin, and Missouri were close states (Dewey barely won the first one).

Answer 3

From what I've read, it was no secret among the Democrats meeting at the 1944 convention that Franklin Roosevelt was terminally ill. He had melanoma and high blood pressure (triple digit both upper and lower figures). Some of the information about Franklin Roosevelt's health during the war years seems to be missing if I'm not mistaken, but the delegates were well aware that whoever was nominated as vice-president would become president of the United States, were Roosevelt to win, which was almost a given in 1944.