How can I go back to review and edit my Delaware state tax entries? Having got to the end, I can no longer get back to the step-by-step screens.

You only need to click on State Taxes at the top of the desktop program screen.  Then click on Continue.  On the following screen click on Edit for the state shown.  Then click on the blue button labeled Go over Delaware again

Thank you. I never did see a "Go over Delaware again" button, but I misspoke when I said I'd gotten to "the end." I'd only gotten to the "When will you file question," where I stopped because I wasn't finished checking.  After I guessed a date and completed the Estimated taxes portion it let me go back to the beginning.