Exhibit 1.1 VAN KAMPEN UNIT TRUSTS, SERIES 786 TRUST AGREEMENT Dated: August 21, 2008 This Trust Agreement among Van Kampen Funds Inc., as Depositor, The Bank of New York Mellon, as Trustee, Ibbotson Associates, Inc., as Supervisor, sets forth certain...Trust Agreement • August 21st, 2008 • Van Kampen Unit Trusts Series 786
