Lou Gehrig was one of the greatest athletes of the twentieth century. He died in his prime from the disease often named after him. On July 4, 1939, he gave his retirement speech, which I copied below.
Some career highlights from Wikipedia:

He was an All-Star seven consecutive times, a Triple Crown winner once, an American League (AL) Most Valuable Player twice, and a member of six World Series champion teams. He had a lifetime .340 batting average, .632 slugging average, and a .447 on base average. He hit 493 home runs and had 1,995 runs batted in (RBI).

He had a rare disease we now call ALS, which results in rapidly increasing paralysis, difficulty in swallowing and speaking, and a life expectancy of less than three years, though full mental functions.

By the end of April, his statistics were the worst of his career, with one RBI and a .143 batting average. Fans and the press openly speculated on Gehrig’s abrupt decline. James Kahn, a reporter who wrote often about Gehrig, said in one article:

I think there is something wrong with him. Physically wrong, I mean. I don’t know what it is, but I am satisfied that it goes far beyond his ball-playing. I have seen ballplayers ‘go’ overnight, as Gehrig seems to have done. But they were simply washed up as ballplayers. It’s something deeper than that in this case, though. I have watched him very closely and this is what I have seen: I have seen him time a ball perfectly, swing on it as hard as he can, meet it squarely — and drive a soft, looping fly over the infield. In other words, for some reason that I do not know, his old power isn’t there… He is meeting the ball, time after time, and it isn’t going anywhere.

On June 21, the New York Yankees announced Gehrig’s retirement. The doctors of the Mayo Clinic had released his ALS diagnosis to the public on June 19. There was then a public push to honor Gehrig.

New York Mayor Fiorello La Guardia called Gehrig “the greatest prototype of good sportsmanship and citizenship” and Postmaster General James Farley concluded his speech by predicting, “For generations to come, boys who play baseball will point with pride to your record.”

Yankees Manager Joe McCarthy, struggling to control his emotions, then spoke of Lou Gehrig, with whom he had a close, almost father-and-son–like bond. After describing Gehrig as “the finest example of a ballplayer, sportsman, and citizen that baseball has ever known”, McCarthy could stand it no longer. Turning tearfully to Gehrig, the manager said, “Lou, what else can I say except that it was a sad day in the life of everybody who knew you when you came into my hotel room that day in Detroit and told me you were quitting as a ballplayer because you felt yourself a hindrance to the team. My God, man, you were never that.”

On July 4, 1939 Gehrig delivered what has been called “baseball’s Gettysburg Address” to a sold-out crowd at Yankee Stadium:

Fans, for the past two weeks you have been reading about the bad break I got. Yet today I consider myself the luckiest man on the face of the earth. I have been in ballparks for seventeen years and have never received anything but kindness and encouragement from you fans.

When you look around, wouldn’t you consider it a privilege to associate yourself with such fine looking men as are standing in uniform in this ballpark today? Sure, I’m lucky. Who wouldn’t consider it an honor to have known Jacob Ruppert? Also, the builder of baseball’s greatest empire, Ed Barrow? To have spent six years with that wonderful little fellow, Miller Huggins? Then to have spent the next nine years with that outstanding leader, that smart student of psychology, the best manager in baseball today, Joe McCarthy? Sure, I’m lucky.

When the New York Giants, a team you would give your right arm to beat, and vice versa, sends you a gift—that’s something. When everybody down to the groundskeepers and those boys in white coats remember you with trophies—that’s something. When you have a wonderful mother-in-law who takes sides with you in squabbles with her own daughter—that’s something. When you have a father and a mother who work all their lives so that you can have an education and build your body—it’s a blessing. When you have a wife who has been a tower of strength and shown more courage than you dreamed existed—that’s the finest I know.

So I close in saying that I might have been given a bad break, but I’ve got an awful lot to live for. Thank you.

There is no known intact film of Gehrig’s speech; only a small snippet of the newsreel footage has survived, incorporating his opening and closing remarks: “For the past two weeks you have been reading about the bad break I got. Yet today I consider myself the luckiest man on the face of this earth. When you look around, wouldn’t you consider it a privilege to associate yourself with such fine looking men as are standing in uniform in this ballpark today?…that I may have been given a bad break, but I have an awful lot to live for. Thank you.”

The crowd stood and applauded for almost two minutes. Gehrig was visibly shaken as he stepped away from the microphone, and wiped the tears away from his face with his handkerchief. Babe Ruth came over and hugged him as a band played “I Love You Truly” and the crowd chanted, “We love you, Lou”. The New York Times account the following day called it “one of the most touching scenes ever witnessed on a ball field”, that made even hard-boiled reporters “swallow hard.”