CHARLESTON, South Carolina (CNN) -- Scientists released video pictures Friday of their first look 137 years into a historic moment of the United States' Civil War-era past.
Scientists at the Warren Lasch Conservation Center in Charleston, South Carolina, released pictures Friday of the inside of the confederate submarine H.L. Hunley, the first sub to sink an enemy ship.
The pictures showed mostly silt, mud and clay. The next step in the process is removal of artifacts and the remains of the nine-man crew that was aboard the sub when it sank off Sullivan's Island, South Carolina on February 17, 1864.
The excavation of the inside of the sunken Confederate submarine H.L. Hunley began earlier this year at the Warren Lasch center.
On the night of the sub's final voyage, its crew targeted and rammed the Housatonic, a Union ship that was part of a naval blockade cutting Charleston off from seagoing traffic during the Civil War.
Hunley, powered by a hand-cranked propeller, was fitted with a long spike on its forward tip. At the end of the spike was an explosive device that was inserted into the Housatonic's hull when Hunley rammed it. The ship exploded and was destroyed in the blast.
Minutes later, Hunley sank with all crew members aboard. By excavating the submarine, scientists and historians hope to learn why Hunley sank. Despite its sinking, Hunley was a mechanical marvel ahead of its time. The next submarine to sink an enemy ship didn't do so until 50 years later.
Hunley was missing for 136 years after it went down. It was finally discovered in 2000, after an exhaustive search by author Clive Cussler, who has spent much of his life searching for lost ships.
Hunley, sitting under about 30 feet of water, was brought to the surface on August 8, 2000. Since then, experts have been examining the vessel's hull and a thick rock-like coating that had developed over time on the sub's surface.
Earlier this week, scientists had opened hull plates that had covered Hunley's crew compartment so they could probe inside the craft's interior.
To offset the cost of the estimated $17 million salvage and restoration project, South Carolina has provided $3 million and the U.S. Department of Defense has provided $2 million.