Secret Service (Fallout 2)

The United States Secret Service was an United States federal government law enforcement agency, operating under the auspices of the Enclave following the Great War and the organization succeeding the American government. Their primary mission was the protection of the President at any and all cost (although since 2077 that'd be more of a representative position) and to this end they carried the best available equipment. In 2242, they employed Advanced Power Armors and Pulse Rifles together with a squad of Sentry Bots and other support.

Frank Horrigan, during his tenure as the Presidential Bodyguard, would be considered a part of the Secret Service.