Exhibit 1.1 VAN KAMPEN UNIT TRUSTS, SERIES 780 TRUST AGREEMENT Dated: July 21, 2008 This Trust Agreement among Van Kampen Funds Inc., as Depositor, The Bank of New York Mellon , as Trustee, Van Kampen Asset Management, as Supervisor, sets forth...Trust Agreement • July 21st, 2008 • Van Kampen Unit Trusts Series 780
