Final answer:
In 1964, President Lyndon B. Johnson's speech during the Civil Rights Act signing ceremony was not interrupted by protesters; instead, it was a moment where he addressed the nation to sign this important legislation.
Step-by-step explanation:
In 1964, during the Civil Rights Act signing ceremony, protesters did not actually interrupt a speech by President Johnson. President Lyndon B. Johnson signed the landmark Civil Rights Act of 1964 on July 2, addressing the nation on national television without significant disruption. This act notably prohibited discrimination based on race, religion, gender, or national origin, effectively ending the enforcement of 'Jim Crow' laws, and it strengthened the enforcement of school desegregation and voting rights. Although the broader civil rights movement did involve various protests and events that disrupted political processes, the signing of the Civil Rights Act itself was a culmination of these efforts and was not marked by an interruption of the kind described in the options provided.