Exhibit 1.1(b) Nuveen Unit Trusts, Series 20 Trust Indenture and Agreement Dated: September 1, 1998 This Trust Indenture and Agreement by and between John Nuveen & Co. Incorporated, as Depositor and The Chase Manhattan Bank, as Trustee, sets forth...Trust Indenture and Agreement • September 1st, 1998 • Nuveen Unit Trusts Series 20
