President John F. Kennedy's Attorney General was his younger brother, Robert F. Kennedy (RFK), who served from 1961 to 1964, playing a crucial role in civil rights, fighting organized crime, and advising the President on major foreign policy decisions like the Cuban Missile Crisis, acting as his closest confidant. 

The last spike used to complete the first transcontinental railway was made of gold (specifically, a 17.6-carat gold alloy), though it was ceremonial and later removed, replaced by regular iron spikes, with other gold, silver, and iron spikes also presented for the event, all symbolizing the historic achievement. 

Compact discs (CDs) are read from the inside out, while vinyl records are read from the outside in, with the CD laser starting at the center and moving outwards, and the vinyl needle starting at the outer edge and moving inwards. This difference is due to their fundamental design: CDs use a laser scanning a spiral track from the center, while vinyl records physically groove from the edge inward, following the path of the cutting stylus.