Final answer:
The event out of sequence is B Chavez's Migrant Workers' March, as it is not directly related to the immediate legislative actions following the Birmingham Church Bombing, like the Civil Rights Act of 1964 and the Voting Rights Act of 1965.
Step-by-step explanation:
The event of the 1960s Civil Rights Movement that is out of sequence on the timeline is B Chavez’s Migrant Workers’ March. The Birmingham Church Bombing occurred in 1963, immediately followed by significant legislative responses. The Civil Rights Act of 1964 was passed after President Johnson rallied behind it due to the tragic bombing. Subsequently, in 1965, the Voting Rights Act of 1965 was enacted to further combat racial discrimination in voting. Chavez's Migrant Workers' March, led by labor leader and civil rights activist Cesar Chavez, is not directly associated with these events and is part of a different thread of the civil rights movement focusing on the rights of farm workers.