What was the primary long-term effect of rosa park’s refusal to give up her seat on the bus in 1955?

The primary long-term effect of Rosa Parks' refusal to give up her seat on the bus in 1955 was the start of the Montgomery Bus Boycott, which was one of the first steps of the Civil Rights Movement.

Explanation:

In response to Rosa's incarceration, Martin Luther King, a relatively unknown Baptist pastor at the time, led the protest to the Montgomery public buses, simply summoning the African-American population to organize themselves to transport themselves and not take the buses. As the buses ended up receiving few or no passengers, they began to deficit, so it became necessary for the public transport authority to end the practice of racial segregation on the buses. This event initiated more protests against other segregation practices still in force at the time, and evolved later in the major scale Civil Rights Movement.

Meanwhile, in 1956, the judicial fight against the segregationist laws of Montgomery and Alabama finally reached the Supreme Court of the United States, which declared transportation segregation unconstitutional.