| Antietam Creek | |
|---|---|
 Burnside's Bridge traversing Antietam Creek near Sharpsburg, Maryland, site of heavy combat during the Battle of Antietam (Sharpsburg) on September 17, 1862 | |
  Location of mouth in Maryland | |
| Location | |
| Country | United States |
| States | Maryland,Pennsylvania |
| Physical characteristics | |
| Mouth | |
• coordinates | 39°25′02″N77°44′47″W / 39.41722°N 77.74639°W /39.41722; -77.74639 |
| Length | 41.7 mi (67.1 km) |
| Basin size | 290 km2 (110 sq mi) |
| Basin features | |
| River system | Potomac River |
Antietam Creek (/ænˈtiːtəm/) is a 41.7-mile-long (67.1 km)[1]tributary of thePotomac River located in south centralPennsylvania and westernMaryland in theUnited States, a region known as theHagerstown Valley. The creek became famous as a focal point of theBattle of Antietam during theAmerican Civil War.
The creek is formed inFranklin County, Pennsylvania, at the confluence of the West and East Branches of Antietam Creek, about 2.3 miles (3.7 km) south ofWaynesboro, Pennsylvania.Welty's Mill Bridge crosses the East Branch of Little Antietam atWashington Township inFranklin County, Pennsylvania. The stream runs for about 0.5 miles (0.80 km) upon its enteringWashington County, Maryland. The course proceeds southward in a meandering pattern, and the creek empties into thePotomac south ofSharpsburg[2] about 50 miles (80 km) upstream ofWashington.[3]
Thewatershed area is 290 square miles (750 km2) and includes parts of Franklin County (106 mi2) and Washington County (185 mi2).[4]: 3 Major tributaries in Pennsylvania include the East and West Branches, Red Run and Falls Creek. Major tributaries in Maryland include Little Antietam Creek, Beaver Creek, and Marsh Run. Communities in the watershed include Waynesboro in Pennsylvania; andBoonsboro,Funkstown,Hagerstown,Mount Aetna, Sharpsburg andSmithsburg in Maryland.
At least four different tributaries are named Little Antietam Creek. Little Antietam Creek which empties into the Antietam inKeedysville, Maryland and another belowLeitersburg, Maryland. The name Little Antietam Creek is also applied to the East and West Branch in Pennsylvania,[5][6] the West Branch historically Little Antietam Creek proper.[6] These names are listed in theUnited States Geological Survey as variants.
The term "Antietam" is thought to derive from anAlgonquian phrase meaning "swift-flowing stream".[7] Historical and variant names include Andiedom, Andirton Creek, Ant-eat-em Creek, Anticturn Creek, Antieatum Creek, Crooked Brook, Odieta Creek and Ondieta Creek.[2]
The creek is noted for numerous well-preserved stonearch bridges dating to the 19th century that still traverse the creek, the most famous of which is the 125-foot-long (38 m)Burnside's Bridge in theAntietam National Battlefield.
The creek was a major topographic feature during theBattle of Antietam or Sharpsburg, fought on September 17, 1862, near the creek's mouth.[3] Burnside's Bridge became a major focus of combat asUnion forces under GeneralAmbrose Burnside repeatedly tried to capture the bridge fromConfederate forces guarding the crossing from a high bluff overlooking the creek. The day of the battle is known as "the day Antietam Creek ran red" due to the blood of thousands of Union casualties mixing with the creek waters. Both sides lost about a fourth of their number[8] but, despiteGeneral McClellan's refusal to press on his attacks,[8] it served as a tactical Union victory, asLee was forced to withdraw fromMaryland.
Most of the watershed area is relatively rural in nature, but the area surrounding Hagerstown is threatened byurban sprawl. The area is also heavily cultivated, and wasterunoff from farms is a growingwater quality concern. TheMaryland Department of the Environment (MDE) has identified farm runoff as the largest source of sediment (loose soil) in Antietam Creek and its tributaries. The second largest source isurban runoff.[4]: 11 MDE recommends that farmers implementbest management practices on their lands to control runoff, such as installingriparian buffers.[4]: 34
