what famous american poet used the first lines of her poems as their titles?

Answer 1

The responder is correct in commenting that Dickinson didn't title any of her poems, but the first lines have been attributed as their default titles.

Another American poet whose poems' titles are often their first lines is Edna St. Vincent Millay.

Answer 2

Emily Dickinson?
I know her family found over 800 of her poems after she had died and that is when the bulk of her work was published. They were originally without title, so these were added posthumously.

Answer 3

Emily Dickenson. And she didn't do it herself, actually. She didn't title anything, and her poems were published after she died. Since there were no titles, the publishing company used the first lines instead.