Inside look at how 25,000 National Guardsmen are arriving in Washington, DC

Thousands of National Guardsmen from across America are arriving daily in Washington, D.C., as they build up to the 25,000 members authorized to help provide security at next week's presidential inauguration in the wake of the assault on the U.S. Capitol.

Bringing in so many guardsmen has been a major logistical feat in just a matter of days has been a major logistical feat after the Secret Service requested that the number of personnel increase from15,000 to 25,000. The number of guardsmen in the city will be a military force five times larger than the number of U.S. troops in Iraq and Afghanistan combined.

"To bring them from every state in the nation on short notice -- that many folks -- is truly an incredible feat," Gen. Daniel Hokanson, the chief of the National Guard Bureau, told ABC News.

ABC News accompanied Hokanson as he visited Joint Base Andrews in suburban Maryland, where as many as 40 military flights a day are bringing guardsmen from all 50 states and three territories to assist with security at the inauguration.

Hokanson said that as the Secret Service increased its request for more guardsmen to help provide security his team contacted every state to see if it could help provide personnel.

"Everyone answered to come in and provide that level of support," said Hokanson.

By the end of Saturday, 11,000 guardsmen will have arrived in the Washington, D.C., area as part of the security mission and the full 25,000 will be in place by Wednesday's Inauguration Day.

"I would guess that we're probably breaking records with the National Guard completely for this kind of mobilization stateside and getting people moved this quickly," said Lt. Col. Alysia Benson, the Force Support Squadron commander of the 113th Wing of the D.C. Air National Guard, who is helping to coordinate the airlift of guardsmen to Washington.

Benson said that it would normally take months to coordinate so many flights into one location, but "we just basically jumped in and made it happen on pretty much a moment's notice as things started to evolve." It's been particularly difficult at Joint Base Andrews, which does not typically see so many inbound and outbound flights and does not have the infrastructure of some of the military's major transportation hubs.

"I've never seen anything in my 18 years in the military of this scope go this quickly," said Benson. "All things considered, it's moving along really smoothly considering the amount of time we had."

Hokanson said coordinating the transportation of so many guardsmen has been impressive given that they had to quickly transition from their civilian jobs.

"Day to day they're working with their employers or in their jobs or with their families," said Hokanson. "We just recalled them as quickly as we can to get them here, but we truly are a part-time force; we call ourselves citizen soldiers."

While some guardsmen are arriving via ground transportation from neighboring states, many are arriving on "gray tail" flights being flown by the Air National Guard.

Newly arrived guardsmen are taken to the base's theater, where they receive instruction on their mission for the inauguration. Most of the units have been mobilized for up to 30 days and could remain in Washington beyond Inauguration Day.

The guardsmen helping to provide security around the U.S. Capitol building and on federal land in the nation's capital will be armed. Others who will be assisting local D.C. police in traffic enforcement beyond that area will not be armed.

Hokanson said the decision to arm the guardsmen was due to security threats picked up by the FBI and local law enforcement.

"Based on that, my highest priority is to make sure our guardsmen are protected, and they have the right to defend themselves," said Hokanson.

"Our mission here is to protect our people and our property," said Hokanson. "So we're going to do everything to make sure that they're successful."

Photos of guardsmen napping inside the Capitol building earlier this week left the impression that they were without adequate lodging.

The D.C. National Guard had to issue a statement clarifying that guardsmen were napping in between shifts at assigned rest areas, just as they would during other domestic or overseas employments.

Hokanson said taking care of the thousands of National Guardsmen arriving in the city has been a team effort between the National Guard and the Pentagon's contracting personnel.

"They've been able to make sure that all of our soldiers and airmen have adequate lodging, that they're getting their three meals," he said.

And part of that effort includes Benson, who said that for her team, "the biggest thing is to kind of get them in and get them out quickly so they can get to their hotels and then get ready for the mission."