What does it mean by we have also come to this hallowed spot to remind America of the fierce urgency of now.?

The phrase "fierce urgency of now" emphasizes the immediate need for action and change in addressing social injustices and civil rights issues. It conveys that the struggle for equality cannot be postponed any longer, as the present moment demands decisive action rather than complacency. By referring to a "hallowed spot," it underscores the significance of the location in the broader context of the movement, reinforcing the importance of the cause and the necessity to act with urgency.