Jessica Ciencin Henriquez was just trying to get rid of some stuff. She and her 6-year-old son were moving out of their apartment in lower Manhattan, and they couldn’t lug all their possessions out of the country with them.

But when she sat down to write a Craigslist post for her furniture, knickknacks and books at her “Moving On Is Hard To Do Sale” June 15, the Manhattan-based writer ended up penning 2,000 words chronicling her life in New York City — the thrill of new love, the pain of divorce, the pleasures of raising a child — that have taken the Internet by storm.

“It just felt wrong writing, ‘Rug, 8×10, like new,’ ” Henriquez, who was married for two years to actor Josh Lucas, tells The Post. She says she’s received 912 responses to the ad so far and plans to give proceeds to Moms for Moms NYC, a nonprofit that provides assistance to single mothers in need.

“I’m a nostalgic person,” says Henriquez, who shares a son with Lucas. “Each of those items meant more to me than just a quick summary . . . They were significant markers of my growth and evolution, coming to New York City at 22 and leaving at 33.”

For example, there’s the queen-size mattress, bought “at the beginning of my year of celibacy,” she writes — “no stains, no damage, and the tears have dried.”

There’s the four coffee mugs that she no longer needs since “I quit drinking coffee the year I finally quit him,” and the books “I bought from The Strand before I realized shopping was just another way to temporarily soothe a broken heart.”

Finally, she gets to her son’s wooden globe that she and her son would often spin, placing their finger in a random spot, asking, “Would we live there?”

“Sometimes we would end up in the middle of the ocean, and sometimes we would end up in Delaware,” says Henriquez. “But we spun enough times that we ended up somewhere where it was like, ‘Wait, we can go there.’ ”

Henriquez declines to say where she and her son are headed — save that it’s across an ocean and near a beach. But she says writing an inventory of her things has helped the process of letting go.

“[Remembering] how significant those things had been has made me more enthusiastic about passing them on, and having them change somebody else’s life,” she says.