New York City, New York

The Merchant's House Museum may be Manhattan's most haunted place. People inside the 1832 NoHo historic home have reported being touched by ghosts. Halloween-themed events and tours are scheduled throughout October. Over at Landmark Tavern, an Irish restaurant and saloon in Hell's Kitchen, three ghosts — a sailor, a retired soldier and a little girl, all traced to the 19th century — have been spotted by patrons.

Los Angeles, California

The Hollywood Roosevelt Hotel has attracted celebrities since its 1927 opening — some living, some not. Marilyn Monroe has been seen dancing in the ballroom, a ghost has appeared on a security video and guests have been locked out of rooms from the inside. In Long Beach, guests on The Queen Mary, a luxury cruise ship-turned-hotel with year-round paranormal tours, have experienced chilling encounters in the pool area and recorded unexplained banging on engine-room pipes.

Chicago, Illinois

One stop on Chicago haunted tours is Hull-House Museum, a National Historic Landmark and the inspiration for the horror movie “Rosemary's Baby." Jane Addams, the social activist who lived there, is among those who saw ghosts in its rooms. Another stop is the Congress Plaza Hotel, where the more than 1,000 guestrooms have been occupied by presidents and celebrities as well as ghosts — including the hotel's former owner, Al Capone — that move objects and slam doors.

Washington, D.C.

Abe Lincoln was spotted in the White House for decades after his assassination, not surprisingly in the Lincoln Bedroom and the Oval Office by a First Lady and a visiting queen, among others. Close by is Lafayette Square Park, a national historic landmark where the ghost of “Star Spangled Banner" writer Francis Scott Key's only son — murdered there by a jealous husband — haunts the grounds along with other ghosts.

Philadelphia, Pennsylvania

Guards at Eastern State Penitentiary routinely tortured inmates, whose ghosts now get even by spooking caretakers and visitors with cries and whispers. Even Al Capone said a ghost haunted him while he was imprisoned there. Equally spooky is Fort Mifflin, a Revolutionary War fort and battlefield with year-round paranormal programs. Resident spirits include a faceless man and ghost dogs.

New Orleans, Louisiana

The French Quarter is packed with haunted bars, hotels and mansions including the notorious LaLaurie House, an 1832 home where the owner's wife, Delphine, allegedly murdered a young slave girl. Delphine and the victim have both been seen in the mansion. Also in the Quarter is Hotel Provincial, a former Civil War hospital where guests have heard the ghosts of Confederate soldiers conversing at night.

San Francisco, California

Some visitors to the old prison on Alcatraz Island have seen ghost prisoners walking the cellblocks and heard voices in the old inmate cafeteria even when it's empty. In the city's Haight-Ashbury district, birthplace of the hippie movement, many have heard running footsteps on the sidewalk outside Janis Joplin's old Ashbury Street house, where a man was shot in the head while fleeing a gunman in 1969.

Charleston, South Carolina

A headless torso and the ghost of a student who died leaping off the roof have haunted guests at the Battery Carriage House Inn. Another beautifully restored, but equally haunted, early-19th-century building in Old Charleston is the Dock Street Theatre. Its ghostly residents include a woman killed by lightning nearby and actor Junius Brutus Booth, the father of Abe Lincoln's assassin, a former audience member who's been seen watching rehearsals from the balcony.

Gettysburg, Pennsylvania

Many visitors to Gettysburg Battlefield, where 8,900 Civil War soldiers died in a 24-hour period, say they've seen and spoken to “ghost soldiers." Some have even captured audio and video recordings of screams and cannons. Nearby at Farnsworth House Inn, a former Union general's home scarred by more than 100 bullet holes from the battle, nightly ghost walks are offered. To date, 14 apparitions have been seen.

If you go

Visit united.com or use the United app to plan your haunted-city getaway.