Final answer:
The SCLC's voter registration efforts in Selma led to the attack on the Edmund Pettus Bridge, known as 'Bloody Sunday,' a significant event in the civil rights movement.
Step-by-step explanation:
The SCLC's push to register Black voters in Selma, Alabama, prompted the attack on the Edmund Pettus Bridge, often referred to as "Bloody Sunday." This event occurred on March 7, 1965, when peaceful protestors marching for voting rights were brutally attacked by Alabama State Troopers as they crossed the bridge. This violent confrontation was a direct consequence of the SCLC's voter registration campaign in Selma and was a pivotal moment in the civil rights movement, capturing the nation's attention and generating wider support for the cause.