Yes you are correct. Thanks for the correction. I confused the Yalta conference with the Pottsdamn Conference.
Pottsdamn was held in August 1945 to implement the Yalta agreement. Pottsdamn was the conference where the events I wrote about took place. Churhill was defeated in his re-election effort during Pottsdamn and was replaced by Clement Attlee.
Truman complained bitterly that Attlee gave in to every one of Stalin's demands.
It was during that conference that Truman learned the Atomic Bomb worked. Truman told Stalin about the bomb and Stalin did not seem surprised. Truman concluded that Stalin knew all about our Atomic project.
Had we not developed the Atomic Bomb it was estimated that taking Japan would cost 1 million American lives. Both Roosevelt and Truman had worked to get Stalin to commit Russian forces to the invasion of Japan. Stalin agreed but wanted Eastern Europe as pay. That is primarily why Stalin got eastern Europe.
As it turned out the Atomic Bomb fixed it so we did not need Stalin's help ... so we gave up eastern europe for 50 years and got nothing in return.