Washington — In addition to the millions of people who traveled to Washington to witness Barack Obama's historic presidential inauguration Tuesday, thousands of law enforcement officers from across the country volunteered to assist with security for the event.

Fifty-one North Carolina State Highway Patrol troopers were among the officers sworn in Monday as special deputy U.S. marshals for the event.

"This gives the guys and myself a chance to come off the road and do something unique, something extraordinary," said Highway Patrol First Sgt. David Henderson, of Henderson.

Aside from the professional challenge, Henderson said, he jumped at the chance to assist with the inauguration for personal reasons.

"My 5-year-old son is convinced that I'm going to meet President Obama," he said. "He told me, 'When you meet him and shake his hand, tell him my name.' When a 5-year-old is interested in what his father's doing for the change, then somebody's reached out and touched the right person."

The officers assisting with inauguration security came from law enforcement agencies as far away as Los Angeles, Washington state and Fort Worth, Texas. More than 5,600 security cameras also have been set up in and around the inauguration area, and downtown streets were closed to non-commercial traffic Monday.

Before the officers were sworn in, Metropolitan Police Department Chief Cathy Lanier reminded them of their place in history and the challenge of remaining alert and focused.

Highway Patrol Trooper Scott Meade said the history of the moment was the reason he came from Gastonia for the inauguration.

"It's a once-in-a-lifetime situation, to be part of history forever," Meade said. "To be here for the first African-American to be sworn in as president and (the fact that) I can actually be a small part of that is absolutely amazing."