The Anacostia River was once nearly a mile wide and deep enough for ocean-going ships to travel and trade, but by 1850 it had silted in from erosion caused by deforestation and farming and was no longer navigable. In 1912, the Army Corps of Engineers began dredging the river in an attempt to make it passable again for shipping, and in the process thousands of acres of wetlands were filled and destroyed and Kingman and Heritage Islands were formed from dredge spoils. Kingman Island remained federal property until 1996, when it was transferred to the District of Columbia. Today, Kingman and Heritage Islands are District-owned public parkland dedicated to environmental education and the preservation of natural resources. The islands, though entirely man-made and created at the expense of wetland ecosystems more than 100 years ago, now contain important and rare ecosystems including tidal freshwater wetlands, vernal pools, wildflower meadows, and tidal swamp forests. More than 100 species of birds and other wildlife live there, and over the last 20 years students and scientists have restored this freshwater tidal wetland, whose ecosystem now supports wildlife and filters pollution from the Anacostia River as the tide rises and falls each day.
