Blackwater National Wildlife Refuge was established in 1933 as a waterfowl sanctuary for birds migrating along the critical migration highway called the Atlantic Flyway. The Refuge is located on Maryland's scenic Eastern Shore, just 12 miles south of Cambridge, and consists of over 27,000 acres of freshwater impoundments, brackish tidal wetlands, open fields, and mixed evergreen and deciduous forests. Blackwater is one of over 540 units in the National Wildlife Refuge System, which is managed by the U.S. Fish and Wildlife Service.

Blackwater Refuge is fed by the Blackwater River and the Little Blackwater River. The name "blackwater" comes from the tea-colored waters of the local rivers, which are darkened by the tannin that is picked up as the water drains through peat soil in the marshes.

In addition to a wealth of wetlands, Blackwater is also home to over 250 bird species and three recovering species: the endangered Delmarva fox squirrel, the delisted migrant peregrine falcon, and the American bald eagle, which in 2007 was removed from protection under the Endangered Species Act because its population numbers have increased to a healthy level.

Before becoming a refuge, the local land was once managed as a fur farm, and muskrat and nutria (a non-native species introduced from South America) have been trapped here in the past. Just recently, nutria was deliberately eliminated from the Refuge property due to its destructive overeating of the wetlands' plants. In addition to trapping, the land at Blackwater also shows signs of past timbering and farming.

Other forms of human history have also played an important role in the region where Blackwater Refuge resides. Nause and Waiwash were the names of two Nanticoke Indian ancestral villages that were based in Dorchester County, Maryland -- the home of Blackwater Refuge. The Nause-Waiwash Indian tribe now consists of over 250 descendants of the original Nanticoke Indians from the Eastern Shore of Maryland. The tribe has restored their Longhouse at the corner of Maple Dam Road and Greenbriar Road, half a mile from the Refuge, which is adjacent to Fishing Bay Wildlife Management Area. In Fishing Bay are Guinea and Chance islands, the ancestral home of the Nause-Waiwash Indian tribe who still make annual visits there.

Also, the region is steeped in Civil War and civil rights history; nearby Bucktown is the birthplace of Harriet Tubman, one of the conductors of the Underground Railroad. Tubman took over 300 slaves to freedom in Pennsylvania, New York and Ontario, Canada. Blackwater Refuge is believed to be a former hiding place for escaped slaves who were traveling on the Underground Railroad.

In addition to managing Blackwater Refuge, the Blackwater staff also administers the Chesapeake Marshlands National Wildlife Refuge Complex, which in addition to Blackwater NWR, is comprised of Martin NWR, Eastern Neck NWR, Susquehanna NWR and its Barren Island, Watts Island, Bishops Head, and Spring Island Divisions.