Old enough to fight, old enough to vote” became a major rallying cry for which amendment to the Constitution

That would be the 26th Amendment. "The right of citizens of the United States, who are eighteen years of age or older, to vote shall not be denied or abriged by the United Statea or by any State on account on age." (rewritten in simpler terms)

martin luther king (1929-1968) was an activist for the african american rights, mr. king has a profile of a kind leader that built a tenacity, respect and full of hope future. he was an activist through civil disobedience and no violence pressure mechanisms. he tried to build a more egalitarian and fair society. his efforts carried a reivindication message of the civilian rights to every west corners. for that reason, he won the nobel prize in 1964.