Homeland Security’s Shifting Mission Over the Past Quarter-Century
Established after the Sept. 11 attacks to protect the country against terrorism, the agency absorbed immigration functions that have become its focus under President Trump.
In the Trump administration, the Department of Homeland Security functions in part as the president’s arm for conducting the immigration enforcement operations that he made a key campaign promise.
But when the agency was founded in the early 2000s after the Sept. 11 terrorist attacks, the mission was largely focused on coordinating a national strategy to prevent terrorism in the United States.
“The new department will analyze threats, will guard our borders and airports, protect our critical infrastructure and coordinate the response of our nation for future emergencies,” former President George W. Bush said in a 2002 speech before he signed the bill that officially enacted the agency. “The Department of Homeland Security will focus the full resources of the American government on the safety of the American people.”
Here’s what to know about the creation of the Department of Homeland Security, the agency central to President Trump’s agenda on immigration.
2001: The Office of Homeland Security is created.
Days after the Sept. 11 terrorist attacks, Mr. Bush announced in a nationwide address that he was creating a new cabinet-level position reporting directly to him called the Office of Homeland Security.
Its first leader was Tom Ridge, the former governor of Pennsylvania who was a close political ally and trusted friend of the president, but had no experience in the executive branch, counterterrorism or intelligence. His job was to “oversee and coordinate a comprehensive national strategy to safeguard our country against terrorists and respond to any attacks that may come,” Mr. Bush said in a speech.
Mr. Ridge was also tasked with coordinating the efforts of other agency leaders — as many as 46 at the time — to gather intelligence that could prevent another terrorist attack, to protect borders and systems inside the country and to respond immediately if there was another targeted assault.
2002: President Bush signs the Homeland Security Act.
After some back-and-forth with congressional committees in the summer of 2002 to finalize the agency through the Homeland Security Act, Mr. Bush’s original vision for the office and the agencies under it was scaled back.
In the fall of the same year, Congress finalized the act and Mr. Bush signed it into law soon after, officially creating the Department of Homeland Security. It was considered Washington’s biggest transformation in 50 years.
Twenty-two federal departments were moved under the agency, including those overseeing the U.S. border, transportation security, emergency preparations and threat analysis.
A priority for the department at the time was securing borders to prevent terrorist attacks, which made immigration a matter of national security, according to the 2002 proposal by the Bush administration.
The Homeland Security Act also dissolved the Immigration and Naturalization Service and moved the agency’s functions to three separate ones under the new Department of Homeland Security: the U.S. Citizenship and Immigration Services, U.S. Immigration and Customs Enforcement and U.S. Customs and Border Protection.
2017: President Trump makes immigration enforcement a first-term priority.
When Mr. Trump took office in 2017, he quickly made immigration enforcement a priority of his first term.
The administration directed the Department of Homeland Security to prioritize immigration enforcement through several executive orders, including building a wall to protect the border, deporting more undocumented immigrants and limiting travel to certain countries. He also added additional resources to the department.
2025: Trump takes a harsher stance on immigration.
In Mr. Trump’s second term, beginning in 2025, the administration has sought to arrest and deport people living in the United States illegally. It secured an extraordinary injection of funding to help pay for it.
The president has targeted sanctuary cities led by Democrats in targeted enforcement operations, and Kristi Noem, the secretary of the Department of Homeland Security, has sent thousands of agents from C.B.P., ICE and other offices under her to make arrests.
The Trump administration has also removed temporary protected status for some immigrants, instituted travel bans similar to his first term and has challenged birthright citizenship.
The Latest on the Trump Administration
Echoing White Supremacists: A flurry of social media posts from the White House, Department of Labor and Department of Homeland Security have included images, slogans and even a song used by the white nationalist right.
NATO Chief Defends Trump: Mark Rutte, the secretary general of NATO, warned Europe that it could not defend itself without the United States and said that President Trump was “doing a lot of good stuff.”
Nursing Home Rule Revoked: Executives who donated to Trump’s super PAC met privately with him and urged a repeal of a rule, initiated during the Biden administration, that required increased staffing levels in an effort to reduce neglect among residents.
Air Safety: The Federal Aviation Administration is overhauling its internal structure to modernize and increase safety, in a shake-up intended to make the agency more responsive at a time of heightened focus on improving the security of air travel. The changes come one year after two seemingly routine flights above Washington, D.C., ended in a deadly midair collision.
Trump’s War on Federal Workers: With 300,000 employees gone and collective-bargaining rights eliminated, the administration has hobbled organized labor. But it may have also started a movement.
Minnesota Voter Rolls: The Justice Department has urged Minnesota to hand over voters’ private data. It is part of a national push that has raised concerns about the Trump administration’s motives.
I.R.S.: Frank Bisignano is the first chief executive of the agency, where there’s hope he will end a chaotic stretch. The tax filing season is his first test.
How We Report on the Trump Administration
Hundreds of readers asked about our coverage of the president. Times editors and reporters responded to some of the most common questions.