In 1971, Pamela Mason was a college freshman living in Ohio when she got pregnant. She knew immediately that she wanted an abortion, but the procedure was heavily restricted in her state.

Still, she wanted to find a way. The clinic near her university’s campus referred her to an abortion clinic in Manhattan, and when she was about 10 weeks along, Ms. Mason and her boyfriend scraped together enough money to drive to New York City.

Three years before Roe v. Wade established a constitutional right to abortion, New York legalized the procedure in 1970, turning the state into a magnet for women who wanted to terminate their pregnancies but were barred from doing so where they lived.

“I was very relieved because New York was doable. It was 500 miles away,” said Ms. Mason, now 64 and a human resources manager living in New Jersey.