Ridge confidently noted that it had been nearly one year since the administration raised the national threat level. There hasn't been a strike on U.S. soil since Sept. 11, 2001. He said he was certain the country is safer, that terrorists realize its airlines, ports and borders are dramatically more secure.
Then Ridge rapped his knuckles on a wooden podium for luck. He will remain in the job through Feb. 1, partly because of increased risks of a terror attack around the holidays and the presidential inauguration.
Ridge, whose name became synonymous with color-coded terror alerts and tutorials about how to prepare for possible attack, made a formal announcement in front of news media, saying he was proud to work with so many people dedicated to the security of the American public, reported CBS News Correspondent Bob Orr.
Ridge said that for the future he intends to "raise some family and personal matters to a higher priority," including attending his son's rugby games.
Ridge submitted his resignation in writing to President Bush, saying, "I will always be grateful for his call to service," Ridge said.
In an e-mail circulated to senior department officials, Ridge praised the department as "an extraordinary organization that each day contributes to keeping America safe and free."
But, as CBS's Orr reports, his color-coded alerts were often ridiculed and critics complained that the warning system was too vague. Jokes about his advice regarding duct tape flew during chemical warnings.
As the nation's first chief of the new Department of Homeland Security, Ridge presided over a collection of 22 disparate federal agencies and 180,000 employees. He acknowledged he could not prove the enormously expensive and complex security measures put in place since 2001 have foiled any terrorist attacks inside the United States but said he was certain America was safer.
"I am confident that the terrorists are aware that from the curb to the cockpit we've got additional security measures that didn't exist a couple years ago, that from port to port we do things differently with maritime security," Ridge said. "I am confident they know the borders are more secure. I am confident they know we have developed and are sharing information with state and local law enforcement."
Ridge said terrorists know that because of the changes, "America is a different place to work and operate in."
He also said he was privileged to work with the department's 180,000 employees "who go to work every day dedicated to making our company better and more secure."
Among those mentioned as possible candidates for Ridge's replacement are Bernard Kerik, interim Minister of the Interior for Iraq and former New York City police commissioner, former Federal Emergency Management Agency Director Joe Allbaugh and Environmental Protection Agency Administrator Mike Leavitt and White House homeland security adviser Fran Townsend. Others are also believed to be interested in the job, including Asa Hutchinson, undersecretary for border and transportation security in the Homeland Security Department.
Six other Bush Cabinet figures are leaving, including Attorney General John Ashcroft, Commerce Secretary Donald Evans, Education Secretary Rod Paige, Agriculture Secretary Ann Veneman; Secretary of State Colin Powell and Energy Secretary Spencer Abraham. Bush has chosen national security adviser Condoleezza Rice for the State Department, White House counsel Alberto Gonzales for the Justice Department and Carlos Gutierrez for Commerce.
As CBSNews.com's David Paul Kuhn reports, political watchers say Mr. Bush is in a, so he can push his second term agenda. Popular wisdom is that a second term president's political clout quickly wanes.
In October 2001, Ridge became the nation's first White House homeland security adviser, leading a massive undertaking to rethink all aspects of security within the U.S. borders in the wake of the terror attacks of September 2001.
Congress subsequently passed legislation establishing the Homeland Security Department, merging nearly 200,000 employees from 22 government agencies. Ridge became the department's first secretary in January 2003.
He has presided over six national "orange alerts" when the government boosted security out of concern that an attack may be coming. An attack in the United States never happened on his watch.
Ridge has said, however, that he believes an assault by the al Qaeda terrorist network was averted last summer during the Fourth of July holiday period, when intelligence reports indicated terrorists might be targeting international flights to attack the United States. Passenger manifests were scrutinized and flights were canceled.
Yet Ridge, a politician by nature, fought criticism leading up to the election from those who said he was using terror warnings to boost support for President Bush. Ridge repeatedly said: "We don't do politics in the Department of Homeland Security."
Ridge, 59, has privately expressed his interest in moving out of the time-consuming, stressful post. However, those who know him said his loyalty to the president was always a factor to consider.
Ridge, who has spent most of his adult life in public service, came home from Vietnam, earned a law degree and went into private practice in Pennsylvania. He later served as an assistant district attorney and ran for Congress in 1982.
Ridge was re-elected five times. He became the Pennsylvania governor in 1995, leaving the state capital in October 2001 after the White House called.