Final answer:
The passage of the USA Patriot Act prompted an increase in domestic security measures around the United States, expanding federal law enforcement powers for surveillance without a warrant.
Step-by-step explanation:
The Congressional action that prompted an increase in domestic security measures around the United States was the passage of the USA Patriot Act. This law, passed shortly after the September 11, 2001 attacks, expanded the powers of federal law enforcement agencies. It allowed for the use of covert surveillance without a warrant, aiming to detect and prevent terrorist activities within the United States. Additionally, it was part of a broader response to the 9/11 attacks, which also included the establishment of the Department of Homeland Security to centralize control over a number of different government functions for better threat management.
Though the creation of the Federal Emergency Management Agency (FEMA) and the declaration of war on Afghanistan played roles in the United States' response to the 9/11 attacks, it was the Patriot Act that directly led to the described increase in domestic security measures portrayed in the photograph. The Department of Homeland Security was also established as a result of this increased focus on security, but it was the Patriot Act that most significantly augmented government surveillance and law enforcement capabilities.