Simple iron bars that could be used to purchase a human being. Iron shackles clearly designed for a young child's legs. A captain's log that complains of the stifling African heat, but doesn't even mention the cold reality that the ship was dealing in human cargo.

Such are the sights and sounds of A Slave Ship Speaks: The Wreck of the Henrietta Marie, a traveling exhibit of artifacts from a sunken slave ship that will welcome visitors to Baltimore's Reginald F. Lewis Museum of Maryland African American History and Culture when it opens at Pratt and President streets on June 25.

At first blush, the Henrietta Marie seems an unlikely centerpiece for the opening of a museum dedicated to Maryland history. There's no evidence it ever reached the state's shores during its two trans-Atlantic voyages, in 1697-1698 and 1699-1700. But the hardships endured by the enslaved men and women tell a universal story, one museum officials believe dovetails nicely into the story of African-Americans in a former British colony that would, perhaps ironically, come to be known as the Free State.

"We wanted to give people an understanding of what went on prior to becoming an enslaved person here in Maryland," says Margaret Hutto, the museum's exhibits manager.

Judging by the silent testimony of the Henrietta Marie, a wreck discovered off the Florida coast about 30 years ago by divers in search of Spanish treasure, what happened was both horrific and, according to the tenor of the times, unremarkable. There was nothing especially sordid about the ship; it was like hundreds of vessels plying the seas at the time, their crews struggling to earn a profit for investors in England.

That's one aspect of the slave trade the visitors need to understand, says Sandy Bellamy, the museum's executive director. It was just a business, not a social tool or a way to wage war or attempt to enact vengeance on a conquered people.

"Slavery was an economic construction," she says, "out of which grew racism. African-Americans are not inherently inferior, but are a resilient people, who've overcome insurmountable odds."

The exhibit, which has been traveling the United States for about eight years, paints slavery as a simple matter of economics. British consumers wanted produce from the New World - sugar, molasses, spices - and landowners in America needed able bodies to work the land.

Bars of iron ore, each about the size of a 12-inch ruler, would be traded with African tribal leaders, who would offer in return men, women and children from conquered tribes. A case at the museum contains 11 of these simple, unadorned black bars. They alone would have been enough to purchase an enslaved female; for a male, you'd have to come up with another bar or two.

The Henrietta Marie exhibit is filled with such mute testimony to the casual banality of slavery; its existence, at least to the 18th-century mind, was no big moral deal.

The exhibit includes a replica of the ship's hold - the actual wreck remains on the sea bottom, too fragile to be brought to the surface - that gives an idea of what life was like for its human cargo. A group of mannequins, crowding each other on the floor, offers some perspective on what the awful journey from Africa to America must have been like.

"It was an eerie feeling," Hutto says, "putting those mannequins in."

But nothing in the exhibit smacks the visitor harder than the shackles. Hung on a wall across from the mannequins are eight pairs of varying sizes, including a pair no more than a few inches in diameter - clearly designed for young children.

"It brings home the fact that there were more than just adult males and females that were enslaved," says Hutto. "Those shackles really got to me."

The wreck of the Henrietta Marie was discovered in 1972 by salvager Mel Fisher, who was looking for the 17th-century Spanish treasure galleon Nuestra Senora de Atocha. After establishing that the Henrietta wasn't it, Fisher moved on, leaving the wreck undisturbed for the better part of two decades. By then, the historic significance of the wreck had been established; it's the oldest slave ship ever found, according to a 2002 article in the National Geographic, and one of only a handful discovered in American waters.

"When I got here, I thought we could do something with it," says Madeleine Burnside, executive director of the nonprofit research arm of Fisher's operation, the Mel Fisher Maritime Heritage Society, who in 1992 persuaded him to let the society take control of the site. "I didn't know much about the slave trade, but I was pretty sure I hadn't heard of a lot of slave ships being found, anywhere."

Much of what has been brought up from the Henrietta Marie is on display at Fisher's Key West, Fla., museum. But the touring exhibit, sponsored by General Motors, has been spreading the ship's story throughout the United States since 1995.

Like just about everyone else, Burnside has been most affected by the shackles salvaged from the wreck. In all, she says, almost 200 pairs have been recovered. Each one, she says, offers testimony to the human spirit.

"I think of the human ability to resist captivity and always struggle for freedom," she says. "It tells you something about the character of these people, that they were in this horrible situation - they were sick and they had dysentery, they were starved, they were severely dehydrated at all times - and yet they had to be shackled to be kept down. That tells you something right there."