MONTPELIER, Vt. – The importance of the border between Canada and the United States since the Sept. 11, 2001, attacks has grown.

Now the nation has three times as many staff members devoted to securing the border and searching for illegal immigrants. That has led to a record number of arrests in the nation and in Vermont.

The Department of Homeland Security has 1,048 people patrolling the U.S.-Canadian border, compared with the 334 before Sept. 11, 2001.

The department, which was created by Congress after the attacks, employs some 2,200 people in Vermont with a payroll of $96 million.

Some of those people are deployed 94 miles away from the border at a checkpoint on Interstate 91 at White River Junction, one of about 100 sites miles from a border throughout the country.

Since just before the new year, 414 illegal aliens have been arrested at that Vermont checkpoint, which is staffed by four or five people per shift.

The number of people trying to enter the United States illegally has increased in the past year, after an initial decline after Sept. 11.

“A lot of the groups that tried to smuggle people in were wary about doing that because of what the government did after the attacks,” said Leslie Lawson, a spokeswoman for the U.S. Border Patrol sector headquarters in Swanton.

“Now those groups seem to be resuming what they were doing,” she said.

Her office is responsible for monitoring the border between official entry points, covering the stretch from Ogdensburg, N.Y., to the Maine-New Hampshire border. It has four stations in Vermont: Beecher Falls, Newport, Richford and Swanton.

Since Oct. 1, her office has been responsible for arresting 2,554 people seeking to enter the country illegally. During the previous 12 months, they arrested 1,852 people.

Vermont has 15 entry points along its 117-mile border with Canada, the busiest ones in Highgate Springs and Derby Line. In addition to monitoring Vermont’s border with Canada, a considerable number of federal employees in the state play important roles in keeping tabs on the activities of noncitizens throughout the country.

The Williston-based Law Enforcement Support Center provides information on the immigration status and criminal records of noncitizens.

Employees at the center scan eight immigration databases containing 93 million files. They respond to electronic inquiries from state and local law enforcement agencies. The average response time is five to seven minutes.

The center employs 266 people, compared with 194 employees before the terrorist attacks.