Silly Canadian, Educate Your own self:
http://www.dhs.gov/creation-department-homeland-security
Department Creation
Eleven days after the September 11, 2001, terrorist attacks, Pennsylvania Governor Tom Ridge was appointed as the first Director of the Office of Homeland Security in the White House. The office oversaw and coordinated a comprehensive national strategy to safeguard the country against terrorism and respond to any future attacks.
With the passage of the Homeland Security Act by Congress in November 2002, the Department of Homeland Security formally came into being as a stand-alone, Cabinet-level department to further coordinate and unify national homeland security efforts, opening its doors on March 1, 2003.
I am a lot older than 2001 / 2002. You know the Coast Guard and INS and lots of other things happened before the DHS was ever a thought.