Based on the clue 'august 21 half a million people march through the ...', what is the answer?

What is associated with: august 1914 is a novel about the first days of wwi by this author of the gulag archipelago? What is associated with: august 1983 saw the first night launch of this reusable us orbital vehicle? What is associated with: august 2 1923 in san francisco california? What is associated with: august 21 1968 this nation invaded by russians and four other warsaw pact forces? What is associated with: august 22 1962 when his limousine was attacked near paris? What is associated with: august 22 1989 this pitcher fans 500th? What is associated with: august 23 1959 she joins charlie browns family as his younger sister? Based on the clue 'august 23 is the feast of st rose of this capital ...', what is the answer?