JACKSONVILLE, Fla. -

The Republican-controlled House and the Democrat-controlled Senate could not agree on a spending plan by midnight, so what was deemed the nonessential services of the federal government shut down overnight.

It is the first government shutdown in 18 years.

The shutdown will stop 800,000 federal government workers or contractors from getting paid and could cost the economy about $1 billion a week.

So what does this mean for Jacksonville?

Active duty troops will still get paid. The Senate approved a House-approved measure Monday to ensure members of the military would continue to get paid during the shutdown. Obama signed off on it just before midnight.

"You and your families deserve better than the dysfunction we're seeing in Congress," the president said in a video message to troops and Defense Department employees early Tuesday morning.

About 1,000 civilian employees of the Florida National Guard were given furlough notices Tuesday morning. About 100 of them are in north Florida. "This furlough is not expected to exceed 30 calendar days," a letter to staff reads.

DOCUMENT: Furlough guidance from U.S. Office of Personnel Management

"I don't know if the people in government realize how hard and long our human resources works and how much paperwork it takes ... and how much it really costs -- the bottom dollar -- to shut everything down," said Crystal McMairy, a National Guard employee, as she joined other people in closing down her office Tuesday morning.

Active-duty National Guard will continue on the job, and the adjutant general of local guardsmen said he has the option to call back employees in the event of an emergency.

"We can bring people in on state on active duty to support in the event of a hurricane or storm," Gen. Emmett Titshaw said. "And, under emergency authority, I can bring people back in to protect life limb or property in an emergency situation. But under normal circumstances, they are gone and not being paid for the rest of the week."

The 2,500 civilian employees of the Fleet Readiness Center Southeast -- aircraft maintenance facility at NAS Jacksonville -- will continue to work and get paid, the Navy told Channel 4.

It's uncertain how the shutdown will affect military veterans, including the 3.3 million who are disabled.

If the shutdown stretches into late October, the Veterans Affairs Department -- meaning disability and pension checks could stop for elderly and ill veterans.  Processing of disability appeals and other administrative services will be reduced.

Rear Adm. V. Guillory (retired), who is director of Military, Veterans and Disabled Services for the city of Jacksonville, said ship movements and flight operations at area Navy bases may be reduced or suspended during the shutdown.

National parks and museums in the area are closed.

In Jacksonville, that means the Fort Caroline National Memorial and Timucuan Ecological and Historic Preserve and Kingsley Plantation are not open. City parks with in Timucuan remain open.

Not only were visitors forced to turn around Tuesday, but employees now have to worry about getting paid. Park officials for Fort Caroline and Timucuan say 30 of their 32 employees were sent home on furlough.

"Some of our employees live paycheck to paycheck, and so they will get a paycheck today for the last two weeks. Then we don't know what happens after that," parks superintendent Barbara Goodman said.

In St. Augustine, Castillo De San Marcos and Fort Matanzas are not open.