Answer:
The "Big Three" leaders were Truman, Stalin and Winston Churchill.
Step-by-step explanation:
On July 17th, 1945, the leaders of the "big three" nations met for a third conference in Potsdam, Germany. The Soviet Union was represented by Joseph Stalin, Britain by Prime Minister Winston Churchill and the United States by President Harry S.Truman. The Potsdam Conference was the first of the three conferences that President Truman attended, as President Roosevelt, who died in April 1945, had attended the previous two.