The planes hijacked on September 11, 2001, departed from three cities:

• Boston, Massachusetts: Both American Airlines Flight 11 and United Airlines Flight 175 took off from Logan International Airport in Boston, headed for Los Angeles

• Washington, D.C. area: American Airlines Flight 77 departed from Washington Dulles International Airport, headed for Los Angeles

• Newark, New Jersey: United Airlines Flight 93 took off from Newark International Airport, bound for San Francisco

Thus, the three cities from which the hijacked planes originated were Boston, Washington (Dulles), and Newark.