Armed with a sleeping bag, whistle, flashlight and journal Joseph McGill is ready to spend another night in a strange place -- a building that once housed slaves.

This week, the program officer with the National Trust for Historic Preservation, will sleep in a former slave dwelling in Egypt, Texas.

The unusual sleepover is part of his push to preserve buildings that once housed slaves, and it's just one of the overnight excursions the Charleston, South Carolina, man has planned around the country this year.

"It is usually those iconic places -- the big house, the house on the hill, the architecturally significant houses -- that are saved, and very few of the places that tell the story of African Americans," said McGill.

"Slave dwellings certainly tell that story," he added. "It's not one of those happy stories."

McGill's independent project is in its second year. Last summer, he spent the night in 10 slave cabins in South Carolina and Alabama.

This year, which marks the 150th anniversary of the start of the Civil War, he has expanded the project to Texas, North Carolina, Louisiana, Maryland and Missouri.

McGill, 49, first had the idea for the project in 1999 when he slept in a slave cabin at Boone Hall Plantation near Charleston as a Civil War re-enactor in the all-black 54th Massachusetts Volunteer Regiment.

He feels that maintaining the buildings is an important aspect to preserving the story of slavery in America.

The Atlantic slave trade ended in 1808. But the domestic slave trade continued, and many slaves were not freed until months after the Civil War ended in 1865.

"There are a lot of plantation houses left, but a lot of those plantations don't have the outbuildings anymore," McGill said. "They deteriorated. They fell, demolition by neglect. That's forgivable.

"But if someone intentionally got rid of them trying to forget or erase that part of history, I can't forgive that," he said.

During his overnight stays, McGill said he thinks about the lives of slaves who shared the space. He's found shards of glass, animal bones and other artifacts in the buildings he has visited.

Given that the slaves likely had no beds, "I always sleep on the floor," he said. "I may change that in Texas because of scorpions."