EXHIBIT 1.1 VAN KAMPEN UNIT TRUSTS, TAXABLE INCOME SERIES 138 TRUST AGREEMENT Dated: July 11, 2008 This Trust Agreement among Van Kampen Funds Inc., as Depositor, The Bank of New York Mellon, as Trustee, Standard & Poor's Securities Evaluations, Inc.,...Trust Agreement • July 11th, 2008 • Van Kampen Unit Trusts Taxable Income Series 138
