On May 15, a special train will leave Providence to make a trip 15 miles north and 150 years into the past.

The excursion is being organized by the Blackstone Valley Tourism Council to honor the 150th anniversary of Abraham Lincoln’s visit to Rhode Island and his speech at Woonsocket’s Harris Hall. Riders will pay $49.50 each to take the train with Robb Dimmick, a Lincoln interpreter — never call them impersonators — who will walk the cars and converse about the issues of the day. The day being 1860, that is.

Upon arrival at the train depot in Woonsocket, the riders will visit a new exhibit, “Free Ride,” on the abolitionist movement in Woonsocket before heading to Harris Hall, where Dimmick will deliver an abbreviated version of Lincoln’s famous Cooper Union Speech. Named for the hall in New York City where he spoke, the speech laid out Lincoln’s argument as to why slavery should not be allowed to expand into the territories.

The speech, which Lincoln was said to have worked harder on than any other in his life, was hailed as a definitive justification for preventing the expansion of slavery. It was reprinted across the country, made Lincoln a national political sensation and set him on the path to the presidency.

Donna Houle, who is organizing the event for the tourism council, said the group will then get back on the train with “Lincoln” and return to Providence at about 3:30 p.m. Tickets can be ordered from the council’s Web site — www.tourblackstone.com/lincolntrain.htm

Besides seeing Dimmick’s portrayal up close, Houle said, the package includes performances at the Woonsocket depot and Harris Hall by the Providence Brigade Band, a Civil War-period brass band, and a signed commemorative print from an original painting by artist Peter Campbell. The original painting will be raffled off during the ride, she said.

Lincoln’s 1860 visit happened in March, as he was returning from visiting his son at Phillips Exeter Academy in New Hampshire. At the request of Latimer Ballou, a Woonsocket mill owner and a founder of the state’s Republican Party, Lincoln stopped off in Woonsocket to reprise the themes he hit in the Cooper Union Speech. He delivered it in Harris Hall, which now serves as City Hall.

The original version of the speech ran about 90 minutes, Houle said, and with the assistance of former Rhode Island Supreme Court Chief Justice Frank Williams, a leading Lincoln expert, it has been pared down to about 20 minutes for Dimmick to deliver at 11 a.m. and 1 p.m..

Williams said the speech is not what 20th-century ears are accustomed to hearing. Rather than producing sound-bite lines that can be quoted free of context, Lincoln’s address was more like a lawyer’s brief, Williams said, with each part building on what came before and setting up what would come next. It charted how the Founding Fathers compromised on slavery, showing a majority never intended it to expand into the territories, a major issue in 1860.

By dropping the history lessons from the speech, Williams said Dimmick will deliver what Lincoln called “a few words to the Southern people,” which was really a call to slavery’s opponents. Lincoln closed with the quote that today is cast in bronze and bolted to the side of the federal courthouse in Providence

“Let us now have faith that right makes might,” he said, “and in that faith, let us, to the end, dare to do our duty as we understand it.”

jhill@projo.com