WASHINGTON (7News) — It is one of D.C.’s hidden treasures. Nearly 450 acres of Northeast D.C. is a tree park — The U.S. National Arboretum.

It was converted from farmland and forest in the 1930s and early 1940s by hundreds of young Black men from D.C. who were part of the Civilian Conservation Corps (CCC).

The current Arboretum Director, Dr. Richard Olsen, spoke with 7News about the piece of land where the CCC’s Camp Hamilton once stood.

“We had a large group of men that needed to be put to work during the depression, mainly local boys,” Dr. Olsen said.

“They did something on the order of six and a half miles of roads, six bridges, earthen ponds that we still have today, food trails,” said Dr. Olsen, “They prepared the grounds, moved about 15,000 cubic feet of soil.”

Some of the images Dr. Olsen showed us of the young Black D.C. men had never been publicly released before. They showed the barracks where the men slept and the tasks at which they worked.

See more at WJLA-7 News