With its unconventional style and structure, “Little Boy” wasn’t an easy sell at first. When Mr. Lord submitted a partial manuscript to publishers in 2016, six editors said they were interested, but no one made an offer. Mr. Ferlinghetti wavered.

“Ferlinghetti said, take it off the market, nobody’s going to buy it,” Mr. Lord said.

But Mr. Lord isn’t one to give up easily. In the 1950s, when he was representing Jack Kerouac, he spent several years trying to sell “On the Road,” which every major publishing house rejected. Even Kerouac told Mr. Lord to stop submitting it, but Mr. Lord kept at it, and finally got an offer from Viking for a $900 advance. Mr. Lord insisted on $1,000. “On The Road” was finally published in 1957.

Mr. Lord was confident that someone would want to publish the latest work from Mr. Ferlinghetti, one of America’s most successful and beloved poets.

“I felt it was a crime to let it sit there,” Mr. Lord said. “I said, ‘Lawrence, it’s too good, I want to take it out and try again.’ And he said, ‘See, that’s why you’re the best agent in town!’”