[The series and its rules are explained here, where you will also find links to the songs for the other states.]
15:1. Iowa: 'I've never had a way with women, but the hills of Iowa make me wish that I could'. (1, 2, 3.)
15:2. Iowa: 'Iowa / Is a witch'. (1.)
15:3. All I Owe Ioway: 'I owe Ioway all I owe'. (1, 2, 3.)
15:4. Iowa City: 'Girls, the boys aren't cheap in Iowa City'. (1, 2.)
15:5. Heart Attack And Vine: 'Better off in Iowa, against your scrambled eggs'. (1, 2, 3.)
15:6. Sweet Home Chicago: 'From there to Des Moines, Iowa'. (1, 2, 3.)
15:7. Iowa Stubborn: 'Oh, there's nothing halfway / About the Iowa way to treat you'. (1, 2, 3.)
15:8. Love On A Greyhound Bus: 'When the driver mistook Illinois for Iowa'. (1, 2.)