The highway crossed over the Mississippi River and sliced through flat farmland just west of New Orleans. Smokestacks billowed plumes in the distance. One road sign announced a chemical plant. Another warned of a nearby prison. “Do not pick up hitchhikers,” it said.

After turning onto River Road, I passed faded clapboard houses and a ramshackle grocery store, where a trio of men sat in the sweltering shade of the sagging front porch.

It was July 3, and on the radio, WWOZ played Jimi Hendrix’s “Star-Spangled Banner.” Host Andrew Grafe implored his listeners, “What does it mean to be free? I want you all to think about that.”

Freedom was already on my mind.

I was on my way to Whitney Plantation, a museum in Wallace, La., that is unlike any other between New Orleans and Baton Rouge. The onetime sugar operation where hundreds of slaves toiled for more than a century was transformed for an uncommon mission: to immerse visitors in the harsh, everyday lives of the enslaved.

In creating the museum, more attention went to making monuments and restoring buildings such as a jail for runaways and a blacksmith shop as fixing up the site’s Creole mansion. Sprawling oaks dangling Spanish moss line a walkway that leads to the house’s main entrance — like at other nearby plantations — but here, visitors enter from the back, the way enslaved cooks once did. No one in a hoop skirt talks brightly about “the servants” during a tour of Whitney Plantation.

Louisiana’s heavy summer heat simmered when I parked my car. The dashboard thermometer registered an outside temperature of 101 at 2:50 p.m.

“I was twelve year old when freedom come,” the story on my entry ticket began. Inside the visitors center waiting for my guided tour, I was already delving into the world of the enslaved. The ticket bore the name of Pauline Johnson, and included a memory she shared with the Federal Writers’ Project in the late 1930s, when she was “about 93.”

“Us daddy he work de ground he own on Sunday and sold the things to buy us shoes to put on us feet and clothes. The white folks didn’t give us clothes.” Just before freedom came, her father fell sick and died.

When our guide called for the 3 p.m. tour, a collection of 25 people — a nearly even mix of blacks and whites — gathered in hushed respect, tinged with unease. Many of us were unsure what we would see, and how it would make us feel.

Slave economy

“America got its wealth on the backs of slaves,” said my tour guide, T-Chae.

We stood before the black granite “Wall of Honor” inscribed with the names of people enslaved on the plantation.

Susana, Jasmin, Samba, Auguste: the wall lists 101 Africans and 253 men and women who were bought on the domestic slave market after international trade was halted in 1808. Engraved among the names are images of a slave market, a man’s back crisscrossed with scars, and harrowing snatches of slaves’ stories. A sister was taken many nights to the Big House by her master. An illiterate man would have received 25 lashes had he been found with paper and pencil.

At another stop, the Antioch Baptist Church, sculptures of children scattered among pews give form to the enslaved. Each of the realistic clay works represents a slave depicted on an entry ticket. The church, which was given to the museum by a nearby congregation, had been built by freed slaves who in 1868 started the Anti-­yoke Society, from which the name is derived.

At a small plot of sugar cane planted on the grounds, T-Chae explained how slaves were forced into the fields before the sun rose, brandishing machetes to cut down the thick stocks — and occasionally slicing a leg, instead. She told us how slaves inside the sugar mill stoked fires to boil the cane in large pots, which sometimes spilled thick, scorching liquid onto anyone around. Kettles are lined up in front of a collection of cypress-­wood slave cabins.

I entered one of those cabins, dark even in the daylight. During the time of slavery, a dozen or more people would be squeezed into it for rest. With few windows and no insulation, the shack would have been sweltering in summer and frigid on winter nights. As for privacy, that was a luxury slaves didn’t know.

Nearby stood a jail for runaways. I stepped inside a small steel cage, felt the force of the summer’s heat intensified by metal, and quickly backed out.

At the end of the tour, we were invited to a memorial so grim, it was tucked away; visitors could choose to see the brutal visual, or not. Four rows of clay-sculpture heads on stakes rise before a white picket fence. They are a reminder of the largest slave revolt in the U.S., when 500 enslaved men rose up in 1811, damaged property and killed two white men before they were met by overpowering force. Dozens of the men were beheaded. Their bloodied remains were planted along River Road and in New Orleans’ Jackson Square, a warning for all to see.

Plantation history

T-Chae told us about the plantation’s history. In 1752, German immigrant Ambroise Heidel purchased the land that would become Whitney Plantation and began growing indigo. His son expanded and transitioned to sugar. Two generations later, by the mid-1800s, more than 100 slaves churned out 407,000 pounds of sugar in one season.

After the Civil War — when freedom for blacks looked like another form of bondage, sharecropping — the land passed through many owners, including a New Yorker, who gave the place its current name, and a chemical company with designs to build a rayon factory. When that effort became mired by opposition, white New Orleanian John Cummings bought the 250-acre plantation in 1999. Slowly, as he wiped off the property’s cobwebs, he came to understand the depth of the horror and the trading of human life that had animated the place for more than 100 years. Cummings has spent more than $8 million of his own funds creating a plantation museum focused on slavery. The doors opened in 2014.

“The folks who live around here, a lot of them are descendants of Whitney slaves,” T-Chae explained as the tour came to an end. Freedom may have come after the Emancipation Proclamation in 1863, but money didn’t. “Most people just became sharecroppers in the area because they didn’t have the means to leave,” she said.

When asked, she allowed that, yes, she is a descendant of slaves. In fact, she believes that her great-great-grandfather lived in the very cabin we had passed through.

“For me, this is personal,” she said.

Cummings hopes that the slavery experience grows more personal to every Whitney Plantation visitor.

“We live under a tremendous weight of slavery now,” he told journalists with the Atlantic after the museum opened. “And this isn’t black history we’re talking about. This is our national history. It’s my history. It’s your history.”

Inside the visitors center, a wall has been turned over to people’s reflections as they learn about — and grapple with — slavery. It has come to look like a patchwork quilt of pink, blue and yellow Post-it notes, stitching together a communal response. They speak of slavery’s reverberations through generations, of heartbreaking lessons, of anger, forgiveness and transcendence.

One begins, “I am changed.”