What is associated with: august 21 1968 this nation invaded by russians and four other warsaw pact forces?

What is associated with: august 19 1946 in hope arkansas? 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? Based on the clue 'august 21 half a million people march through the ...', what is the answer? 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?