The protest was triggered by the arrest of African American seamstress Rosa Parks on December 1, 1955. She was charged for violating racial segregation laws in Montgomery, Alabama, after refusing to give her seat on a bus to a white man.
The full story says that she was sitting in the fifth row (the first row that blacks could occupy), along with 4 other blacks. Soon, all of the first four rows were filled up, and a white man walked on. Since blacks and whites couldn't be in the same row, the man wanted all of the blacks to move. The other four blacks complied, but Rosa refused
Rosa Parks was a seamstress by profession and she was also educated. Shortly before her arrest in December 1955, she had completed a course in "Race Relations" at the Highlander Folk School in Tennessee. Rosa Parks was also secretary for the Montgomery chapter of the NAACP.
The boycott was planned before Rosa Parks' arrest. Her arrest was a test case which allowed them to challenge segregation on public buses. Community leaders had been waiting for the right person to be arrested, a person who would anger the black community into action, who would agree to test the segregation laws in court, and who, most importantly, was "above reproach." She was arrested on Thursday, December 1, 1955, for refusing to give up her bus seat to a white passenger. When found guilty on Monday, December 5, 1955, she was fined $10 plus a court cost of $4, but she appealed. Rosa Parks also helped and supported the Montgomery Bus Boycott. Rosa Parks is now considered one of the pioneering women