Don Draper's third child name is Eugene Scott Draper and was named after his dead grandfather. In the episode we can see in his birth certificate that he was born on June 21st 1963 at 4:58 AM
Betty: Where's Don?
Nurse: He's in the waiting room.
Betty: Bullshit! He's never where you expect him to be.
The death that Sally Draper is focused on is of social rights activist, Medger Evers, who was assassinated on June 12, 1963. A vision of Evers later appears in Betty's drug-induced fog during birth. Her mother's words refer to Evers when she warns her what could happen is you speak out against your lot in life.
Lane: You've obviously seen The Bridge on the River Kwai. The Bridge on the River Kwai was a movie that came out in 1957.
Pete: Tell the folks at Admiral that Karl Marx says everythings ok. Karl Marx was a German philosopher and political theorist who has been credited as the foundation of communism.