The contingency plan developed after 9/11 also had its first real test that day: The Senate convened in a pro forma session at one of several secure locations selected to house the chamber should the Capitol be uninhabitable.
Still, officials say, perhaps the most significant changes are those that the public might never know about: classified programs to thwart conventional, chemical, biological and even nuclear weapons and suicide bombers.
“There’s so much of what goes on [around] the Hill that is classified,” said former Senate Sergeant-at-Arms Bill Pickle, who served from 2003 to 2007. “The biggest changes are the ones that are not the most readily apparent, and that’s the way it should be.”
Terri Henderson, 6, center, whose mother is El Salvador, attends a rally with members of Congress at Union Station's Columbus Circle to announce the Restore Opportunity, Strengthen, and Improve the Economy (ROSIE) Act on July 29, 2014. The legislation provides incentives for government contractors to pay a living wage and other benefits that would help low-income workers.