Which agency under the Department of Homeland Security is primarily responsible for security at airports?

The Transportation Security Administration (TSA) is primarily responsible for security at airports, which includes the screening of passengers and their baggage to ensure safety in the air travel sector. Established in response to the events of September 11, 2001, the TSA's main mission is to safeguard travelers while promoting the nation's mobility. It implements various security protocols, such as the screening of passengers using advanced technology and trained personnel, to prevent potential threats.

In contrast, other agencies like the Federal Protective Service focus on securing federal properties, while Customs and Border Protection is involved in border security and the enforcement of customs regulations. Immigration and Customs Enforcement chiefly handles immigration enforcement and investigations relating to customs violations. Thus, the TSA's unique role in airport security distinctly marks it as the agency tasked with ensuring the safety of the nation’s civil aviation.