Looking at his game log, the last day his average was officially below .400 was July 24. He was hitting .436 (!) on June 6! On September 12, he was hitting .413. (The photo above was taken July 1, 1941, at Yankee Stadium.)
(It's a good thing the Red Sox did not fulfill Williams's request to be traded the previous season. In mid-August 1940, Williams told the Boston American: "I don't like this town. I don't like the people. I want to get out of town, and I'm praying that they trade me.")
1960 - Williams plays his final game at Fenway Park -- and the last game of his career. We all know he homered in his final time at bat,
I wrote about the recent edition of John Updike's famous essay on the game here. You can read the (slightly different) original here.