Final answer:
After the Montgomery Bus Boycott, Martin Luther King Jr. formed the Montgomery Improvement Association (MIA) to lead the boycott and organize the black community in Montgomery.
Step-by-step explanation:
After the success of the Montgomery Bus Boycott, Martin Luther King Jr. and other African American ministers formed the Montgomery Improvement Association (MIA). The MIA organized and led the boycott, spreading the word among the black community in Montgomery. This organization played a crucial role in the boycott's success and marked the rise of Martin Luther King Jr. as a prominent leader in the Civil Rights movement.