What is associated with: after the 1957 season these 2 pro baseball teams packed up moved to california?

Based on the clue 'after that pretzel incident she said you will be g...', what is the answer? What is associated with: after the 1881 gunfight at the ok corral virgil earp lost his job as this citys marshall? What is associated with: after the 1930s this replaced coal tar as the major source for aromatic compounds? What is associated with: after the 1940 nazi invasion of this country vidkun quisling took power there? What is associated with: after the 1960 season the washinton senators left the capital headed west becoming this new te… What is associated with: after the 1968 nh primary this democrat announced his candidacy 3 months later he was assassin… What is associated with: after the 1979 electoral defeat of the labour party she took over for prime minister james cal… What is associated with: after the 1987 rejection of this mans nomination to the court anthony kennedy filled powells s…