Final answer:
The Montgomery Improvement Association, formed to organize the bus boycott, happened third in the text , which was responsible for organizing the boycott and spreading word about it to the community.
Step-by-step explanation:
The event that happened third in the text is the formation of the Montgomery Improvement Association.
After Rosa Parks' arrest, a group of African American ministers met to discuss the response, and they decided to organize a boycott of the Montgomery Bus System.
This led to the formation of the Montgomery Improvement Association, which was responsible for organizing the boycott and spreading word about it to the community.