Name The Year: Yosemite Valley is discovered in California.?

Questions

what smash 1971 tune ran eight minutes and 27 seconds?

what 1936 quasi-documentary has been known as tell your children, doped youth and love madness?

who was the leader of czechoslovakia when the russians rolled in, in 1968?

what carly simon hit became the music for a heinz ketchup commercial?

who heard it through the grapevine in 1968?