July 4, 1939: the Yankees celebrate "Lou Gehrig Appreciation Day". Gehrig, up until months prior had put together a career-spanning streak of 2,130 consecutive games played, but was now forced out of action permanently by amyotrophic lateral sclerosis and was dying unbeknownst to the public. Gehrig delivered his famous "Luckiest Man on the Face of the Earth" speech in pregame ceremonies dedicated to him. Wiki link